Polymers of olefinically unsaturated diisocyanates (iii)

ABSTRACT

POLYISOCYANATO-CONTAINING POLYMERS OBTAINED VIA THE VINYL POLYMERIZATION OF UNSATURATED DIESTER DIISOCYANATES AS EXEMPLIFIED BY BIS(2-ISOCYANATOETHYL) FUMARATE WITH/ WITHOUT ETHYLENICALLY UNSATURATED COMPOUNDS, E.G., STYRENE, VINYL ACETATE, ETC., WHICH HAVE UTILITY IN THE MANUFACTURE OF FOAMED PRODUCTS, COATINGS, REINFORCED PLASTIC MATERIALS AND OTHER AREAS.

May 18, 1971 1-. BROTHERTON ETAL 3,579,432

POLYMERS 0F OLEFINICALLY UNSATURATED DIISOCYANA'I'ES (III) Original Filed Nov. 9, 1964 STRESS STRAIN CURVE f f/ 900 I Z Loading A V eoo- I 3 b LnJ I (I) STRAIN (E) IN V MN! '01: s THOMAS K. BROTHERTON JOHN W.LYNN

A 7' TORNE V United States Patent US. Cl. 26077.5 14 Claims ABSTRACT OF THE DISCLOSURE Polyisocyanato-containing polymers obtained via the vinyl polymerization of unsaturated diester diisocyanates as exemplified by bis(2-isocyanatoethyl) fumarate with/ without ethylenically unsaturated compounds, e.g., styrene, vinyl acetate, etc., which have utility in the manufacture of foamed products, coatings, reinforced plastic materials, and other areas.

This application is a division of application Ser. No. 409,921 now US. 3,427,346 entitled, Novel Olefinically Unsaturated Diisocyanates and Products Therefrom, by T. K. Brotherton and I. W. Lynn, filed Nov. 9, 1964 which, in turn is a continuation-in-part of application Ser. No. 212,480 abandoned, entitled Novel Olefinically Unsaturated -Diisocyanates anl Process For Preparation, by T. K. Brotherton and I. W. Lynn, filed July 25, 1962, all of the aforesaid applications being assigned to the same assignee as the instant application.

This invention relates to novel diisocyanate compositions and to processes for preparing the same. In one aspect, the invention relates to novel polymers of the abovesaid diisocyanate compositions which polymers contain a plurality of ethylenic bonds, i.e., C=C In another aspect, the invention relates to novel polymers of the abovesaid diisocyanate compositions, said polymers containing a plurality of pendant isocyanato groups, i.e., NCO. In a further aspect, the invention relates to novel compositions which result from the reaction of novel polyisocyanates with active hydrogen compounds. In various other aspects, the invention relates to the preparation of novel cast resins, thermoplastic resins, millable gum stocks and the cured products therefrom, prepolymers, elastomers, elastic and relatively non-elastic fibers, urethane foams, adhesives, coatings, and the like.

The novel ester diisocyanate compounds which are contemplated can be represented by Formula I infra:

OCNR( JR1(3ORNCO wherein R represents a member selected from the group consisting of divalent, substituted and unsubstituted aliphatic, alicyclic, and aromatic groups, and wherein R represents a divalent Olefinically unsaturated aliphatic group; with the provisos that (1) when both R variables are alkylene groups, e.g., ethylene, R is not a cis-vinylene group, i.e.,

c=o and (2) each isocyanato moiety, individually is at least two carbon atoms removed from the o 0 o i R i o moiety of the above formula. Preferred compounds are those wherein R represents a divalent hydrocarbon group containing from 2 to 12 carbon atoms and R represents a divalent Olefinically unsaturated hydrocarbon group containing from 2 to 24 carbon atoms. Particularly preferred compounds represented by Formula I are those wherein R represents a member selected from the group consisting of alkylene, alkenylene, alkynylene, arylene, arylenealkylene, alkylenearylene, alkarylene arylenealkenylene, alkenylenearylene, arylenealkynylene, alkylenearylene, cycloalkylene, cycloalkenylene, alkycycloalkylene, alkylcycloalkenylene, cycloalkylenealkyene and cycloakenylenealkylene groups containing from 2 to 12 carbon atoms; and R represents an alkenylene group containing from 2 to 18 carbon atoms and more preferably from 2 to 10 carbon atoms.

Illustrative novel diisocyanate compounds encompassed within Formula I supra include, among others,

bis(Z-isocyanato-ethyl) fumarate, bis(2-isocyanato-2-methylethyl) fumarate, bis(2-isocyanatol-methylethyl) fumarate,

bis 9-isocyanatononyl) fumarate bis(12-isocyanatordodecyl) glutaconate, bis(2-isocyanato-n-propyl) fumarate, bis(4-isocyanatophenyl) alpha hydromuconate, bis(2-isocyanatonaphthyl) itaconate, bis(4-isocyanatophenyl) fumarate, bis-(3-isocyanatocyclohexyl) glutaconate, bis(4-isocyanato-2-butenyl) fumarate, and the like.

The term substituted as used throughout the specification and appended claims is meant to further define the novel diisocyanates, the derivatives thereof, and the polymeric products thereof, to include those wherein the aforementioned -R groups (of Formula I) can be aliphatic with alicyclic or aromatic substitutents; alicyclic with aliphatic or aromatic substituents; or aromatic with aliphatic or alicyclic substituents in addition to other groups hereinafter indicated.

Broadly, the generic inventions are directed to novel diisocyanates (of Formula I supra) and to novel processes for preparing the same. Within the limits of the aforesaid generic inventions there are included several highly desirable embodiments which are described hereinafter in detail.

In one embodiment, highly useful and attractive subclasses of novel ester diisocyanates which fall within the metes and bounds of Formula I supra are those wherein each R represents a substituted or unsubstituted divalent aliphatic group and R represents a divalent olefinically unsaturated aliphatic group containing from 2 to 24 carbon atoms. Preferred compounds Within this em bodiment are those represented by Formula II infra:

wherein R represents a divalent substituted or unsubstituted aliphatic group containing from 2 to 12 carbon atoms and R represents an alkenylene group containing from 2 to 24 carbon atoms. Particularly preferred compounds within this embodiment are those wherein R is a member selected from the group consisting of alkylene, alkenylene, alkynylene, cycloalkylalkylene, cycloalkenylalkylene, and aralkylene groups containing from 2 to 10 carbon atoms and R has the same value as previously indicated. The divalent R groups can be either straight or branched chain and need not be the same throughout the molecule.

Illustrative of the novel diisocyanates which fall within this embodiment include bis(Z-isocyanatoethyl) fumarate,

bis 3-isocyanatopropyl) glutaconate, bis(4-isocyanatobutyl) alpha-hydromuconate, bis(S-isocyanatopentyl) beta-hydromuconate,

bis(7-isocyanatoheptyl) itaconate, bis(2,2-dimethyl-3-isocyanatopropyl) fumarate, bis(3-ethyl-5-isocyanatopentyl) glutaconate, bis(3,4-diethyl-S-isocyanatopentyl) alpha-hydromuconate, bis(4,4-dimethyl-6-isocyanatohexyl) beta-hydromuconate, bis(2-methyl-4-ethyl-6-isocyanatohexy1) itaconate, bis(9-isocyanatononyl) fumarate, bis('5,6,7-triethyl-9-isocyanatononyl) fumarate, 2-isocyanatoethyl 3-isocyanatopropyl glutaconate, 4-isocyanatobutyl 6-isocyanatohexyl alpha-hydromuconate, 3-isocyanatopropyl 8-isocyanatooctyl beta-hydromuconate, S-isocyanatopentyl 6-isocyanatohexyl itaconate, 2-methyl-3-isocyanatopropyl 2-isocyanatoethyl fumarate, 4ethyl-7-isocyanatoheptyl 6-isocyanatohexyl fumarate, bis(4-isocyanato-2-butenyl) glutaconate, bis(4-isocyanato-2-butenyl) itaconate, bis(2-isocyanatoethyl) citraconate, bis(7-isocyanato-4-heptenyl) fumarate, bis(8-isocyanato-4-octenyl) glutaconate, bis(Q-isocyanato-S-nonenyl) itaconate, bis( 1 isocyanato-6-decenyl) fumarate, bis(3-ethyl-5-isocyanato-3-pentenyl) fumarate, bis(3,4-dimethyl--isocyanato-3-pentenyl) glutaconate, bis(Z-methyl-4-ethyl-6-isocyanato-2-hexenyl) itaconate, bis(5,6,7-triethyl-9-isocyanato-4-nonenyl) glutaconate, 4-isocyanato-2-butenyl 3-isocyanatopropyl fumarate, 4-isocyanato-2-buteny1 5-isocyanato-3-pentenyl glutaconate, 4-ethyl-7-isocyanato-S-heptenyl 6-isocyanato-3-hexenyl itaconate, bis(S-isocyanato-Z-butynyl) glutaconate, bis(7-isocyanato-4-heptynyl) fumarate, bis(10-isocyanato-4-decynyl) glutaconate, bis (9-isocyanato-5-nonynyl) itaconate, bis(2-phenyl-3-isocyanatopropyl) fumarate, bis(3-naphthyl-5-isocyanatopentyl) fumarate, bis(3-styryl-S-isocyanatopentyl) glutaconate, bis (4-tolyl-6-isocyanatohexyl) itaconate, bis(6-cumenyl-7-isocyanatoheptyl) glutaconate, bis(S-xylyl-8-is0cyanatooctyl) furnarate, bis(7-mesityl-9-isocyanatononyl) glutaconate, bis(2-cyclohexyl-3-isocyanatopropyl) itaconate, 1bis(3-cyclohexyl-5-isocyanatopentyl) fumarate, bis(4-cyclohexyl-fi-isocyanatohexyl) fumarate, bis (S-cyclohexylmethyl-7-isocyanatoheptyl) glutaconate, bis( 3-cyc1oheptyl-S-isocyanatopentyl) itaconate, bis(3-cyclohexenyl-5-isocyanatopentyl) glutaconate, bis (S-cycloheptenylrnethyl-S-isocyanatooctyl) fumarate, and the like.

In a second embodiment, attractive subclasses of novel ester diisocyanates encompassed within Formula I supra are those wherein each R represents a divalent cycloaliphatic group and which need not be the same throughout the molecule and R has the same value as previously indicated. Preferred compounds within this embodiment are those represented by Formula III below:

wherein R represents a divalent substituted or unsubstituted cycloaliphatic group containing from 4 to 12 carbon atoms and R has the same value as previously indicated. Particularly preferred compounds Within this embodiment are those wherein R is a member selected from the group consisting of cycloalkylene, cycloalkenylene, cycloalknylene, alkylcycloalkylene, alkylcycloalkenylene, alkylcycloalkynylene, alkylenecycloalkylene and cycloalkylenealkylene groups containing from 4 to 10 carbon atoms and R is an alkenylene group containing from 2 to 24 carbon atoms. The divalent cycloaliphatic group need not be the same throughout the molecule.

Illustrative novel ester diisocyanates which are included in the second embodimen re 4 bis(2-isocyanatocyclobutyl) fumarate, bis(3-isocyanatocyclopentyl) fumarate, bis (4-isocyanatocyclohexyl) glutaconate, bis(S-isocyanatocycloheptyl) itaconate, bis 7-isocyanatocyclononyl) alpha-hydromuconate, bis 3-isocyanato-4-cyclopentenyl) beta-hydromuconate, bis S-iso cyanato-6-cycloheptenyl) fumarate, bis[6-isocyanato-7-cyclooctenyl) fumarate, bis(2-isocyanatocyclobutylmethyl) glutaconate, bis(2-isocyanato-Z-ethylcyclobutyl) itaconate, bis [2 2'-isocyanatoethy1) cyclobutyl] furnarate, bis(3-isocyanatocyclopentylmethyl) fumarate, bis(3-isocyanato-2-ethylcyclopentyl) glutaconate, bis[3 (2'-isocyanatoethyl) cyclopentyl] itaconate, bis(5-is0cyanatocycloheptylmethyl) fumarate, bis(3-isocyanato-S-methylcyclohexyl) fumarate, bis(3-isocyanato-5,6-dimethylcyclohexyl) glutaconate, bis 3-isocyanato-4-ethylcyclopentyl) itaconate, bis(3-isocyanato-4,S-dicthylcyclopentyl) fumarate, and the like.

In a third embodiment, highly desirable subclasses of novel ester diisocyanates include those wherein each R (of Formula I) represents a divalent aromatic group which need not be the same throughout the molecule. Preferred compounds within this embodiment are represented by Formula IV infra:

wherein R represents a divalent substituted or unsubstituted aromatic group containing from 6 to 12 carbon atoms and R has the same value as previously indicated. Particularly preferred compounds Within this embodiment are those wherein R is a member selected from the group consisting of arylene, arylenealkylene, alkylenearylene, alkylarylene, arylenealkenylene and alkenylenearylene groups containing from 6 to 10 carbon atoms and R is an alkylene group containing from 2 to 24 carbon atoms. The divalent aromatic groups need not be the same throughout the molecule.

Typical ester diisocyanates encompassed by the third embodiment include The preferred novel ester diisocyanates are composed of carbon, hydrogen, oxygen, and nitrogen atoms. However, the novel diisocyanates can also contain groups such as oxy, thio, polythio, sulfonyl, sulfinyl, carbonyloxy, nitro, cyano, halo, carbonate, and the like.

The novel ester diisocyanates can be produced in relatively high yields by novel processes which involve the reaction of the corresponding ester diamine dihydrohalide starting material, contained in an inert, normally-liquid reaction medium, with a carbonyl dihalide, and thereafter recovering the ester diisocyanate product.

The starting materials for the production of the novel ester diisocyanates of the present invention, as hereinbefore indicated, are the corresponding olefinically unsaturated ester diamines or ester diamine salts. The ester diamine salts can be conveniently represented by the following general formula:

HX-NH2R0 H R1- ORNHz-HX wherein R and R have the same values as shown in Formula I above and HX represents hydrogen chloride, hydrogen bromide, or mineral acids such as sulfuric, phosphoric, and the like. Other acid salts can also be utilized but inasmuch as hydrogen chloride has a common anion with phosgene it is the preferred salt, both from this, as Well as economic considerations.

The preparation of the olefinically unsaturated ester diamines, and their hydrohalides, such as bis(2-aminoethyl) fumarate, bis(2-aminoethyl) fumarate dihydrohalide, bis(4-amir1ophenyl) fumarate dihydrohalide and the like is the subject matter of an application entitled, Novel Amino Esters of Olefinically Unsaturated Polycarboxylic Acids and Process for Preparation, by T. K. Brotherton and I. W. Lynn, Ser. No. 212,481, abandoned filed July 25, 1962, and assigned to the same assignee as the instant invention.

These diamino starting materials are prepared, as indicated in the examples, and in the aforementioned copending application, by the reaction of an olefinically unsaturated polycarboxylic acid halide, such as fumaroyl chloride, and a hydroxy amine hydrohalide, such as monoethanolamine hydrohalide, at a temperature of from about 65 to about 95 C., for several hours. The ester diamine dihydrohalide is then isolated, as for example, by filtration and then washed and dried. By the aforementioned process the ester diamine dihydrohalides can be obtained in yields of about 95 percent and higher. For further information regarding the production of the ester diamines and their hydrohalides reference is hereby made to the disclosure of the aforementioned application.

Eminently suitable starting materials which are useful in the preparation of the novel diisocyanates illustrated by Formula II supra are shown in Formula VI below:

wherein R R and HX are as previously defined. Illustrative starting compounds include the hydrohalide salts of the following olefinically unsaturated ester diamines:

bis(2-arninoethyl) fumarate,

bis(3-aminopropyl) glutaconate, bis(4-aminobutyl) alpha-hydromuconate, bis(S-aminopentyl) beta-hydromuconate, bis(7-aminoheptyl) itaconate, bis(2-methyl-3-aminopropyl) fumarate, bis(2,2-dimethyl-3-aminopropyl) fumarate,

bis 3-ethyl-5-aminop entyl) glutaconate, bis(3,4-diethyl-5-aminopentyl) alpha-hydromuconate, bis(4,4-dimethyl-6-aminohexyl) beta-hydromuconate, bis (2-methyl-4-ethyl-6-aminohexyl) itaconate, bis(9-aminononyl) fumarate, bis(5,6,7-triethyl-9-aminononyl) fumarate, Z-aminoethyl 3-aminopropyl glutaconate, 3-aminopropyl S-aminooctyl beta-hydromuconate, S-aminopentyl 6-aminohexyl itaconate, 2-methyl-3-aminopropyl 3-aminoethyl fumarate, 4-ethyl-7-aminoheptyl 6-aminohexyl fumarate, bis (4-amino-2-butenyl) glutaconate, bis(4-amino-2-butenyl) itaconate, bis(5-amino-3-pentenyl) fumarate, bis(7-amino-4-heptenyl) fumarate,

bis 8-amino-4-octenyl) glutaconate, bis(9-amino-5-nonenyl) itaconate, bis(10-amino-6-decenyl) fumarate, bis(3-ethyl-5-amino-3-pentenyl) fumarate,

Highly desirable ester diamine salts which can be used for the preparation of the novel ester diisocyanates illustrated by Formula III supra can be represented by Formula VII below:

trative diamino starting materials include the dihydrohalide salts of the following:

bis(Z-aminocyclobutyl) fumarate,

bis 3-aminocyclopentyl) fumarate,

bis (4-aminocyclohexyl) glutaconate,

bis S-aminocycloheptyl) itaconate,

bis 7-aminocyclonony1) alpha-hydromuconate, bis(3-amino-4-cyclopentenyl) beta-hydromuconate, bis(5-amino-6-cycloheptenyl) fumarate,

bis 6-amino-7-cyclooctenyl) fumarate, bis(Z-aminocyclobutylmethyl) glutaconate, bis(2-amino-2-ethylcyclobutyl) itaconate,

bis 2 2-aminoethyl cyclobutyl] fumarate,

bis 3-aminocyclopentylmethyl) fumarate, bis(3-amino-2-etl'1ylcyclopentyl) glutaconate,

bis [3 2-aminoethyl cyclopentyl] itaconate, bis(S-aminocycloheptylmethyl) fumarate,

bis 3-amino-5 -rnethylcyclohexy1) fumarate, bis(3-amino-5,G-dimethylcyclohexyl) glutaconate, bis(3-amino-4-ethylcyclopentyl) itaconate, bis(3-amino-4,S-diethylcyclopentyl) fumarate, and the like.

The novel ester diisocyanates exemplified by Formula IV supra can be prepared from the corresponding ester diamine salts having the formula:

0 HX-NHzR4O R1 OR4NHz-HX wherein R R and HX have the same values as previously indicated. Examples of such diamine compounds include the dihydrohalide salts of:

bis(4-aminophenyl) fumarate, bis(Z-aminophenyl) fumarate,

bis 3-aminophenyl) glutaconate, bis(7-amino-2-naphthyl) alpha-hydromuconate, bis(7-amino-1-naphthyl) beta-hydromuconate, bis(4-amino-4-biphenylyl) itaconate, bis(5-amino-2-indenyl) fumarate, bis(4-aminobenzyl) fumarate, bis(4-aminophenylethyl) glutaconate, bis(7-arnino-2-naphthylmethyl) itaconate,

bis [4 3 '-aminopropyl phenyl] fumarate,

bis(4-aminomethylphenyl) fumarate,

bis [2 3 '-amin0propyl) naphthyl] glu taconate,

bis (4-amino-2-methylphenyl) alpha-hydromuconate, bis(6-amino-2,4-xylyl) fumarate, bis(4-amino-3-cumenyl) fumarate, bis(4amino-2-methoxyphenyl) glutaconate, bis(4-aminostyryl) itaconate,

bis(4-aminocinnamyl) fumarate, bis[4(4'-amino-2-butenyl)phenyl] glutaconate,

and the like.

In general, the conversion of the ester diamine or ester diamine salt reactants to the novel ester diisocyanate is accomplished by contacting a carbonyl dihalide, more preferably, by sparging phosgene, through a slurry of the ester diamine or the ester diamine dihydrohalide contained in an inert, normally liquid organic medium at a temperature Within the range of from about 100 C., and lower to about 225 C., more preferably from about 125 C. to about 170 C., and thereafter recovering the novel ester diisocyanate. In either instance, it is believed that the intermediate carbamoyl chloride is first formed from the free amine and subsequently thermally degraded to the diisocyanate at the reaction temperature employed. The process can be conducted in either a batch type or continuous reactor.

In general, the liquid reaction medium employed in the conversion of the ester diamine or ester diamine salt to the corresponding novel ester diisocyanate should be inert to the reactants and stable under the conditions employed. Moreover, it should be easily separable from the resulting ester diisocyanate. Typical inert, liquid media which have been found suitable for utilization in the process of the present invention include, among others, the aromatic hydrocarbons such as toluene, xylene, naphthalene, tetrahydronaphthalene, benzene, biphenyl, cumene, amylbenzene; the cycloaliphatic hydrocarbons such as cyclohexane, heptylcyclopentane, decahydronaphthalene; the chlorinated aromatic hydrocarbons such as chlorobenzene, ortho-dichlorobenzene, 1,2,4-trichlorobenzene; the chlorinated aliphatic hydrocarbons such as carbon tetrachloride, tetrachloroethylene, trichloroethylene; the dialkyl ketones such as diisobutyl ketone, methyl isobutyl ketone, methyl hexyl ketone, diisopropyl ketone; and other organic media such as tetramethylene sulfone, and the like.

Although reaction temperatures within the aforementioned range of from about 100 C. to about 225 C., have been found desirable, temperatures above and below this range can also be employed. However, from economic consideration the optimum yield and rate of reaction are attained within the aforesaid range. The particular temperature employed will be dependent, in part, upon the ester diamine or ester diamine salt starting material. Moreover, the optimum temperature for the conversion of the diamino reactant to the novel ester diisocyanate is influenced, to a degree, by other reaction variables. For instance, in a batch type reactor with ortho-dichlorobenzene as the inert reaction medium, an amine hydrohalide concentration of 25 weight percent, based on the weight of the medium, and a phosgene feed rate of 0.5 to 10 mols per mol of amine hydrohalide per hour, the optimum temperature range is from about 125 C. to about 170 C. At temperatures below 125 C., the reaction times were too long to be practical, while at temperatures above 170 C., the diisocyanato product was, in part, converted to resin ous materials.

The pressure is not critical and the novel processes can be conducted at atmospheric, subatmospheric, and superatmospheric pressures.

Although the novel processes preferably are conducted with phosgene, in its broadest concept the process includes the utilization of any carbonyl dihalide such as carbonyl difiuoride, or carbonyl dibromide. However, for economic consideration phosgene is the preferred carbonyl dihalide. In the preparation of the novel diisocyanates, phosgene can be used in either the gaseous or liquid form.

Inasmuch as the yield and rate of formation of the novel ester diisocyanate product are dependent upon several variables, for example, concentration of the ester diamino reactant, solubility of the ester diamino reactant and phosgene in the reaction medium, reaction temperature, pressure, and rate of addition of the phosgene, no hard and fast rule can be devised regarding the optimum conditions to be employed in practicing the novel processes.

In a preferred embodiment of the present process the ester diamine dihydrohalide is slurried in 1,2,4-trichlorobenzene. Thereafter, gaseous phosgene is then sparged through the reaction mixture at a temperature within the aforesaid range and for a period of time to essentially complete the reaction. After removal of the hydrogen chloride by-product and the chlorinated benzene a crude diisocyanate product is obtained which is defined by known purification techniques such as distillation, recrystallization, washing, and the like.

In practice, it has been found that the mole ratio of phosgene to ester diamine dihydrohalide in the initial reaction medium preferably should be in excess of 3:1, although satisfactory results have been obtained at a lower ratio. When the phosgene subsequently is sparged into the reaction medium feed rates of up to about 10 mols of phosgene per mole of amine per hour are preferred, although higher rates can equally as well be em ployed.

The novel diisocyanates are an extremely useful class of compounds which possess exceptionally attractive and outstanding properties. The reaction products of the novel aliphatic diisocyanates are highly resistant to sunlight or ultra-violet light degradation. For example, the use of the novel diisocyanates as the isocyanate source in the preparation of, for example, polyurethane films, elastic, and relatively non-elastic fibers, coatings, cast elastomers, etc., results in non-yellowing products which have strong commercial appeal as well as performance characteristics. It should be noted that non-yellowing elastomeric and nonelastomeric thread or fiber are in great demand within the industry since the commercial products based on aromatic isocyanates rapidly turn yellow in sunlight. The novel diisocyanates such as bis(2-isocyanatoethyl) fumarate, bis[(Z-isocyanate-l-methyl)ethyl] fu'marate, and others, are non-lachrymators which possess relatively little or no odor at ordinary working temperatures and thus allows for their use without the need for special venting systems and/or face masks. On the other hand, both tolylene diisocyanate, the largest volume commercial diisocyanate, and hexamethylene diisocyanate, the only aliphatic diisocyanate currently available in commercial quntities, are extremely strong, lachrymators.

Isocyanates, as a class, should be considered to be toxic materials with relative orders of toxicity. Using tolylene diisocyanate and hexamethylene diisocyanate as the yardsticks, the following meaningful has been observed. Toxicity by skin absorption: (a) hexamethylene diisocyanate-high toxicity; (b) tolylene diisocyanatemoderate toxicity; (c) bis(2-isocyanatoethyl) fumarate and bis[(2-isocyanato 1 methyDethyl] fumarate-extremely low toxicity. Skin sensitization tests: (a) hexamethylene diisocyanate and tolylene diisocyanate-severe sensitizers; (b) bis(2-isocyanatoethyl) fumarate and his [(2-isocyanate-l-methyl) ethyl] fumarate-extremely mild sensitizers. It should be noted that the practical utility of hexamethylene diisocyanate has been severely limited because of its extremity high toxicity.

With the exception of the highly expensive vinylene diisocyanate (which is an extremely potent lachrymator and undoubtedly highly toxic), the novel diester diisocyanates such as bis(2-isocyanatoethyl) fumarate, bis[(2- isocyanato-l-methyl)ethyl] fumarate, and other diisocyanates encompassed within Formula I supra, appear to be the only known and/or available aliphatic diisocyanates which can undergo polymer forming reactions by both 9 true vinyl polymerization and isocyanate condensation polymerization routes.

Many of the novel diisocyanates such as bis(2-isocyanatoethyl) fumarate and bis [(Z-isocyanato-l-methyl) ethyl] fumarate are relatively inexpensive compounds which can readily compete with tolylene diisocyanate on a commercial scale. Based on presently known processes for preparing vinylene diisocyanate, this latter diisocyanate is definitely not competitive (on an economic basis) with the afore-illustrated novel diisocyanates. Moreover, as indicated previously, vinylene diisocyanate is a potent lachrymator and undoubtedly highly toxic which characteristics place severe limitations on its acceptance and applicability.

Of outstanding importance and utility with regard to the novel diisocyanates is their ability to undergo true vinyl polymerization and isocyanate condensation polymerization. For example, the novel diisocyanates can be homopolymerized or copolymerized with a host of ethylenically unsaturated compounds, e.g., styrene, vinyl chloride, butadiene, isoprene, chloropene, ethyl acrylate, methyl acrylate, etc., through the ethylenic bond of the reactant(s), under conventional vinyl polymerization conditions, to give polymers of varying molecular Weight which contain a plurality of pendant or free isocyanato groups. The following specific equation which is not to be construed as limited in scope illustrates the overall reaction:

bis(2-isocyanatoethyl) fumarate (hereinafter designated as FDI) wherein n is a number having a value greater than one and upwards to several hundred, e.g., from two to 200, and higher, and wherein C=C represents an ethylenically unsaturated organic compound which contains at least one polymerizable ethylenic bond, e.g., vinyl chloride, butadiene, etc. The resulting polyisocyanatocontaining polymers than can be subjected to isocyanate condensation polymerization reactions with an active polyhydrogen compound, e.g., polyol, polyamine etc., as explained hereinafter to give useful three dimensional, crosslinked solid products which can be termed poly(vinyl urethanes), poly(vinyl ureas), etc., depending on the active hydrogen compound employed.

The reaction of the novel diisocyanates of Formula I supra, on the other hand, with an active monohydrogen compound, e.g., monoamine, alkanol, etc., results in novel ethylenically unsaturated compounds which in turn can be polymerized with an ethylenically unsaturated organic compound which contains at least one polymerizable ethylenic bond, e.g., the so-called vinyl monomers, through the polymerizable carbon to carbon double bond, to yield a myriad of polymeric products. The following equations are illustrative of typical reactions:

[- COZCzHiNHCORl J linear poly(vinyl urethanes) linear poly(vinyl ureas) diolefinic compound lineal polyurethanes crosslinked poly(vinyl urethanes) Crosslinked poly(vinyl urethanes) can also be prepared via a one-shot process which involves concurrent vinyl and condensation polymerization reactions, for example:

FDI+HOROH +CH =CHCl crosslinked poly (vinyl urethanes Thus, it is apparent that the novel polyisocyanates perrnit the wedding of low cost vinyl monomers, i.e., ethylenically unsaturated organic monomers which contain at least one polymerizable ethylenic bond, with high performance polyurethanes, polyureas, and the like. This advantage has outstanding significance in the development of a myriad of products (based on the novel diisocyanates) which have exceptionally strong commercial and econom ic attractiveness.

Of the novel diisocyanates, the bis(omega-isocyanatoalkyl) fumarates deserve special mention. Of these, bis- (2-isocyanatoethyl) furnarate (FDI) and bis(2-isocyanato-l-methyl) fumarate (LIFDI) are of high significance since products made therefrom, e.g., elastic films and fibers, thermoplastic resins, cast resins, etc., possess, among other things, outstanding and exceptional characteristics. Bis(2-isocyanatoethyl) fumarate (hereinafter designated as FDI) possesses the following properties: molecular weight254; m -1.4623; melting point52 Cil" C.; boiling point-about 152 C./0.2 mm. of Hg; appearance-crystalline solid; solubility-soluble in most of the common organic solvents, e.g., hexane, heptane, benzene, chlorobenzene, toluene, etc. Bis(2-isocyanato-1- methylethyl) fumarate (hereinafter designated as LIFDI), on the other hand, is a very mobile, water-white liquid, a characteristic which cannot be overemphasized in isocyanate and urethane chemistry as witnessed by the huge success of tolylene diisocyanate (TDI). Further properties of LIFDI include the following: molecular weight- 282; n -1.4719; boiling point144-145 C./0.15 mm. of Hg; and solubility characteristics similar to that of FDI.

Of the several monoand polyisocyanates (excluding the aforesaid vinylene diisocyanate) published in An- 1 1 nalen, 562, pages 122-135 (1949), the only aliphatic diisocyanate which contained a carbon to carbon double bond was Z-butenylene diisocyanate,

OCNCH CH=CHCH NCO As is well documented in the literature, olefinic compounds which contain allylic hydrogen are not considered to be true vinyl monomers in a practical sense. The aforesaid diisocyanate falls into this category.

US. Pat. No. 2,797,232 issued June 25, 1957 is directed to the preparation of so-called hidden polyisocyanates which are obtained via the reaction of hydroxyalkyl-carbamic acid-aryl esters with polycarboxylic acids. These hidden polyisocyanates upon heating to temperatures above 150 C., are purported to yield free polyisocyanates. In accordance with the patentees disclosure, various attempts were made to prepare free polyisocyanate from the hidden polyisocyanate in the applicants laboratory. Firstly, the decomposition or thermal degradation of the reaction product of phenyl N-(Z-hydroxyethyl) carbamate (termed by the patentee as bydroxyethyl-carbamic acid-phenyl ester) and maleic acid anhydride (the sole ethylenically unsaturated acid, anhydride, or acyl halide disclosed by the patentee), i.e., the purported hidden polyisocyanate, failed to result in any recoverably free diisocyanate. In lieu of maleic acid anhydride, the applicants then employed maleic acid, furnaroyl chloride, succinic acid, and adipic acid in the above experiments. Failure to produce any recoverable f-ree diisocyanate was encountered in each instance. These experiments were effected with meticulous care, using sophisticated chemical techniques. Applicants operative Examples 23 through 26 in this specification emphatically and unequivocally establish that by following the teachings of US. 2,797,232, using the most optimum conditions and sophisticated chemical techniques, no recoverable free diisocyanate is obtained from the thermal degradation or decomposition of the hidden polyisocyanate, i.e., the reaction product of phenyl N-(2-hydroxyethyl) carbamate with maleic acid anhydride, maleic acid, fumaroyl chloride, succinic acid, or adipic acid. It should be noted, in passing, that maleate compounds are, in general, sluggish vinyl monomers when compared with fumarate monomers.

In one aspect, the invention is directed to the preparation of novel multifunctional polymers of the novel diisocyanates of Formula I supra. In general, the novel polymers of this aspect, i.e., the homopolymers of the novel diisocyanates, the copolymers of a mixture containing the novel diisocyanates, and the copolymers of a mixture containing the novel diisocyanate(s) and an ethylenically unsaturated organic compound(s) possessing at least one polymerizable ethylenic group, are characterized by the presence of a plurality of pendant isocyanatohydrocarbyloxycarbonyl-containing groups i.e.,

\R/ CORNCO if CORNC O wherein R is a tetravalent saturated aliphatic which possesses two (and only two) carbon atoms in the polymeric chain, wherein each R is a divalent saturated air- 12 phatic radical, wherein each m is an integer having a value of zero or one, wherein the moiety 2. preferably contains up to 24 carbon atoms and preferably still, up to 10 carbon atoms, wherein each R has the values enumerated in Formula I supra; with the provisos that (1) each isocyanato moiety (--NCO) of the above unit is at least two carbon atoms removed from the oxycarbonyl moiety i and (2) each isocyanatohydrocarbyloxycarbonyl moiety, i.e.,

is monovalently bonded to separate carbon atoms, and preferably vicinal carbon atoms which form part of the polymeric chain. Unit IX supra occurs at least once in novel polymers. However, for use in many applications as will become apparent from a consideration of this specification, the novel polymers preferably are characterized by a plurality of the structures identified as Unit IX above, i.e., greater than one and upwards to several hundred, for example, from two to 200, and higher.

A particular eminent class of novel polyisocyanatocontaining polymers which should be highlighted in generic manner are characterized by Unit IXA below:

(IXA) wherein the variables R, R R, m, and x have the values noted in Unit IXA supra.

Those novel polyisocyanatocontaining polymers which contain at least one of, preferaby a plurality of, the structure defined as Unit IXC below, represent a significant contribution to the art, to wit:

(IXC) 0 II-CORNCO l (IIH-CH CORNCOJ g wherein R is alkylene radical which preferaby contains from 2 to 12 carbon atoms. It is preferred that the struc ture defined as Unit IXC represent a repeating unit such that the novel polymer is characterized by at least two and upwards to 200, and higher, of Unit IXC therein. It is further preferred that the R radical be ethylene, trimethylene, tetramethylene, methyl substituted ethylene, or methyl substituted trimethylene.

Novel polymers characterized by one or more (and upwards to 200, and higher) of Unit IXD below represent a highly important embodiment of the invention, that is:

i [CORNCO (IXD) poly [bis 2-isocyanatoethyl) fumarate poly [bis 2-isocyanatol-methylethyl) fumarate] poly [bis 3-isocyanato-n-propyl) fumarate] poly [bis (3 -isocyanato-methylpropyl) fumarate] poly[bis(4-isocyanato-n-butyl) fumarate], and the like;

the copolymers of the bis(isocyanatohydrocarbyl) fumarates with other ethylenically unsaturated organic compounds as illustrated by the copolymers of (1) the bis (omega-isocyanatoalkyl) fumarates such as:

bis( 2)-isocyanatoethyl) fumarate, bis(2-isocyanato-1-methylethyl) fumarate, bis(3-isocyanato-n-propyl) fumarate, bis(3-isocyanato-methylpropyl) fumarate, bis(4-isocyanato-n-butyl) fumarate, and the like; and

(2) other ethylentically unsaturated organic compounds such as styrene, vinyl chloride, vinylidene chloride, methyl acrylate, vinyl methyl ether, methyl methacrylate, Z-ethylhexyl acrylate, vinyl acetate, and/or the diisocyanates of Formula I supra, and the like.

As hereinbefore indicated, the novel polymers of the instant invention are obtained by elfecting polymerization of the novel diisocyanate through an ethylenic group. As a result, each of the polymers obtained is characterized by pendant isocyanato-terminated ester groups along the polymer chain. Depending upon the amount of polymerizable novel diisocyanate employed with other vinyl monomers, the copolymers obtained in accordance With the teachings of this aspect have a wide variety of useful properties and applications. For example, copolymerization of a mixture of styrene, 2-ethylhexylacrylate, and bis(2-isocyanatoethyl) fumarate, in a weight of ratio of 45:50:5, furnished a soft, flexible film. In contrast, when the copolymerization was conducted in the same manner with the respective monomers in a ratio of 70:25 :5 the resulting polymeric film was hard and exhibited little tendency to bend. In addition, by virtue of the highly reactive pendant isocyanato groups, the polymers can be further reacted with active hydrogen-containing compounds to form other novel products useful as coatings, adhesives, castings, foams, and the like.

It is pointed out at this time that the term polymer(s) is used in its generic sense, i.e., this term encompasses within its scope polymers prepared from a sole novel diisocyanate as well as a mixture containing two, three, four, etc., polymerizable monomers, at least one of which is a novel diisocyanate. Thus, homopolymers and copolymers are encompassed within the term polymer. Each of the polymerizable monomers entering into the copolymerization reaction do so in significant quantities. As such, the resulting copolymeric products can be chemically distinguishable from the homopolymeric products 14 which would result from the homopolymerization of the monomers separately.

A distinguishing feature of the copolymeric materials is that at least one of the monomers from which the copolymers are made has both an isocyanate portion and an olefinically unsaturated portion. In addition, the polymers can contain one or more vinyl monomers chemically combined therein. In general, the concentration of the polymerizable monomers chemically combined in the novel polymers can vary over the entire range, e.g., from about 0.5, and lower, to about 99.5 weight percent and higher of the polymerizable reactants chemically combined therein, based on the total weight of said reactants. Those copolymers which contain at least 50 weight percent of vinyl monomer, based on the weight of said polymer, are highly preferred. Those copolymers which contain at least about 50 to about 97 weight percent vinyl monomer, and from about 50 to about 3 weight percent ester diisocyanate are eminently preferred.

The novel polymers can be prepared by reacting an admixture comprising novel diisocyanate(s) with/without a vinyl monomer(s) plus a catalytically significant quantity of a vinyl polymerization catalyst, particularly the free radical producing catalysts, under conventional vinyl polymerization conditions.

The free radical producing catalysts are voluminously documented in the art and well known to those skilled in the vinyl polymerization art. Illustrative thereof are those compounds which contain the divalent OO- unit as exemplified by (1) ROOR wherein R is alkyl, aryl, haloaryl, acyl, etc.; (2) ROOH wherein R is a nonacyl radical such as hydrogen, alkyl, etc.; (3) R"OOH wherein R" is acyl; (4) the azo-compounds; and the like. Specific illustrations include, among others, hydrogen peroxide, dibenzoyl peroxide, acetyl peroxide, benzoyl hydroperoxide, t-butyl hydroperoxide, di-t-butyl peroxide, lauroyl peroxide, butyryl peroxide, dicumyl peroxide, azo-bis-isobutyronitrile, the persulfates, percarbonates, perborates, peracids, etc., such as persuccinic acid, diisopropyl peroxydicarbonate, t-butyl perbenzoate, di-t-butyl diperphthalate, peracetic acid, and the like. Ionic catalysts such as boron trifiuoride and anionic catalysts such as sodium phenyl may also be employed in certain cases.

The catalysts are employed in catalytically significant quantities. In general, a catalyst concentration in the range of from about 0.001, and lower, to about 10, and higher, weight percent, based on the weight of total monomeric feed, is suitable. A catalyst concentration in the range of from about 0.01 to about 3.0 weight percent is preferred. For optimum results, the particular catalyst em ployed, the nature of the monomeric reagent(s), the operative conditions, under which the polymerization reaction is conducted, and other factors will largely determine the desired catalyst concentration.

The vinyl polymerization reaction can be conducted at a temperature in the range of from about 0, and lower, to about 200 C., and higher, preferably from about 20 C. to about 150 C. As a practical matter, the choice of the particular temperature at which to effect the polymerization reaction depends, to an extent, on the variables illustrated above. The reaction time can vary from several seconds to several days. A feasible reaction period is from about a couple of hours, and lower, to about 100 hours, and longer. Preferably, the reaction takes place in the liquid phase.

The vinyl polymerization can, if desired, be carried out in an inert normally liquid organic vehicle. The suitable inert vehicles are preferably those which do not react with either the polymerizable monomer or the ester diisocyanate. In view of the reactivity of isocyanato groups with labile hydrogen-containing materials, the preferred vehicles for the polymerization are those which do not possess active hydrogens or contain impurities which possess active hydrogens. Illustrative vehicles which may be satisfactorily used are the aromatic hydrocarbons such as toluene, xylene, naphthalene, tetrahydronaphthalene, benzene, biphenyl, cymene, amylbenzene; the cycloaliphatic hydrocarbons such as cyclohexane, cyclopentane, decahydronaphthalene; the dialkyl ketones such as acetone, diisobutyl ketone, methyl isobutyl ketone, diisopropyl ketone; the organic esters such as ethyl acetate, and other inert, normal-liquid, organic vehicles.

The molar ratio of polymerizable reactants to vehicle is not particularly critical, and it can vary, for example, from about 1:1, and lower, to about 1:1000, and higher. In general, it is desirable to employ a molar excess of organic vehicle.

The polymerizable monomers used in the copolymerization reaction with the novel ester diisocyanates are preferably the ethylenically unsaturated organic compounds which are free of reactive hydrogen atoms as determined according to the Zerewitinoff test and which will not react with the isocyanato group. These compounds can be used singly or in combinations of two or'more and are characterized by the presence therein ofat least one polymerizable ethylenic group of the type C=C These compounds are well known in the art and include, for example, the alkenes, alkadienes, and the styrenes such as ethylene, propylene, I-butylene, 2-butylene, isobutylene, l-octene, butadiene, isoprene, 1,4-pentadiene, 1,6-hexadiene, 1,7-octadiene, styrene, alphamethylstyrene, vinyltoluene, vinylxylene, ethylvinylbenzene, vinylcumene, 1,5-cyclooctadiene, cyclohexene, cyclooctene, benzylstyrene, chlorostyrene, bromostyrene, .fiuorostyrene, trifiuoromethylstyrene, iodostyrene, cyanostyrene, nitrostyrene, N,N- dimethylaminostyrene, acetoxystyrene, methyl 4-vinylbenzoate, phenoxystyrene, p-vinylphenyl ethyl ether, and the like; the acrylic and substituted acrylic monomers such as methyl acrylate, ethyl acrylate, methyl methacrylate, methacrylic anhydride, acrylic anhydride, cyclohexyl methacrylate, benzyl methacrylate, isopropyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, methyl alpha-chloroacrylate, ethyl alpha-ethoxyacrylate, methyl alpha-acetamidoacrylate, butyl acrylate, ethyl alpha-cyanoacrylate, 2-ethylhexyl acrylate, phenyl acrylate, phenyl methacrylate, alphachloroacrylom'trile, N,N-dimethylacrylamide, N,N-dibenzylacrylamide, N-butylacrylamide, methacrylyl formamide, and the like; the vinyl esters, vinyl halides, vinyl ethers, vinyl ketones, etc. such as vinyl acetate, vinyl chloroacetate, vinyl butyrate, isopropenyl acetate, vinyl formate, vinyl acrylate, vinyl methacrylate, vinyl methoxy acetate, vinyl benzoate, vinyl iodide, vinyl chloride, vinyl bromide, vinyl fluoride, vinylidene chloride, vinylidene cyanide, vinylidene bromide, l-chloro-l-fluoroethylene, vinylidene fluoride, vinyl methyl ether, vinyl ethyl ether, vinyl propyl ethers, vinyl butyl ethers, vinyl Z-ethylhexyl ether, vinyl phenyl ether, vinyl Z-methoxyethyl ether, methoxybutadiene, vinyl 2-butoxyethyl ether, 3,4-dihydro- 1,2-pyran, 2-butoxy-2'-vinyloxy diethyl ether, vinyl 2 ethylmercaptoethyl ether, vinyl methyl ketone, vinyl ethyl ketone, vinyl phenyl ketone, vinyl ethyl sulfide, vinyl ethyl sulfone, N-vinyloxazolidinone, N-methyl-N-vinyl acetamide, N-vinylpyrrolidone, vinyl imidazole, divinyl sulfide, divinyl sulfoxide, divinyl sulfone, sodium vinyl sulfonate, methyl vinyl sulfonate, N-vinyl pyrrole, and the like; dimethyl fumarate, vinyl isocyanate, tetrafluoroethylene, chlorotrifluoroethylene, nitroethylcne, and the like.

As indicated previously, the novel polyisocyanato-containing polymers can contain as many as 200, or more, of the units designated as Units IX through IXD supra. In general, these polymers are in the solid range, and they are substantially linear and non-crosslinked. In an exceedingly important embodiment there can be prepared relatively low molecular Weight polymeric aliphatic multiisocyanates, many of which are pourable, i.e., liquid. In particular, the relatively low molecular weight polymers of bisL'omega-isocyanat-o(C C alkyl)] fum-arates and substituted fumarates deserve special mention in view of their commercial attractiveness in preparing non-yellowing rigid urethane foams, cast resins, thermoplastic resins, coatings, etc., which have high performance characteristics. Polymers of bis(2-isocyanatoethyl) fumarate and bis(Z-isocyanato-l-methylethyl) fumarate are preferred. These relatively low molecular polyisocyanato-containing polymers are characterized by the recurring unit identified as Unit IXC supra, or a mixture of recurring units which fall within the scope of Unit IXC supra. Other vinyl monomers such as styrene, vinyl chloride, vinylidene chloride, vinyl acetate, ethylene, methyl acrylate, etc., may also be copolymerized with the bis[omega isocyanato(C -C alkyl)] fumarate to yield relatively low molecular weight polyisocyanato-containing polymers.

The aforesaid relatively low molecular weight polymers can be prepared via the vinyl polymerization routes discussed previously, using a free radical producing catalyst as illustrated supra, e.g., a compound which contains the unit --OO, under the operative conditions set out above. It will be necessary, however, in the preparation of these telomers or low molecular Weight polymers to employ a normallyliquid organic solvent which possesses a relatively high transfer agent constant as illustrated by the polyhalogenated lower alkanes, e.g., chloroform, carbon tetrachloride, iodoform, bromoform, pentachloroethane, and the like; the various allylic compounds of the type CH =CHCH X (the variable X being, for instance, halogen), and the like. The aforesaid exemplified solvents do not contain functional groups which are reactive with isocyanato groups under the conditions employed. Carbon tetrachloride is the preferred transfer agent. The concentration of the organic solvent is of the order described previously for the inert organic vehicles.

The aforesaid relatively low molecular weight polyisocyanato-containing polymers may more properly be termed telomers since examination thereof has shown the presence of the telogen (the normally liquid orgarn'c solvent) therein. In general, as the preferred telogens are the halogenated aliphatic hydrocarbons, the resulting telomers may be characterized by fragments of the telogen at the terminal sites of the polymeric molecule. For example, with carbon tetrachloride as the organic solvent of choice, the carbon tetrachloride acts in a manner somewhat similar to a chain stopper. Thus, the resulting telomer can be characterized with a chloride fragment and a trichloromethyl fragment at the terminal sites of the polymeric chain thereof. As a rule of thumb, if the telogen is represented by RX wherein X is halo such as chloro, bromo, etc., and R is a monovalent aliphatic hydrocarbon radical or a monovalent monoor polyhalogenated hydrocarbon radical such as alkyl, the chlorinated alkyls, etc., the result ing telomer may be considered to possess the R and X fragments (of the telogen) at the terminal sites of the polymeric molecule.

To a significant degree, the diisocyanate(s) of choice, the organic solvent or telomer of choice, the concentration of the diisocyanate(s) and organic solvent, the purity of the diisocyauate (s), etc., will largely influence the resulting molecular weight of the polymer. Consequently, it will be necessary to one having ordinary skill in the art to correlate, in a routine fashion, the various variables illustrated above as well as the vinyl polymerization operative conditions in order to obtain the desired polyisocyanatocontaining polymeric products.

The novel relatively low molecular polymers which result from this embodiment have average molecular weights ranging up to about 5000, and preferably u to about 2500. These polymers are characterized in that they contain from 2. to about 20, preferably from 3 to about 10, of the units designated as Unit IXC supra.

Of particular importance are the telomers of his [omega-isocyanato (C -C alkyl)] fumarate, citraconates,

17 and itaconates, and especially those which have the recurring units, respectively:

(IXE) and (IX F) wherein 2: equals 2 to about 20, preferably from 3 to about 10.

In one aspect, the invention is directed to the preparation of novel products which result from the reaction of the novel polyisocyanates such as those exemplified by Formula I and Units IX through IXF supra and other novel polyisocyanates exemplified hereinafter with compounds which contain at least one reactive hydrogen as determined according to the Zerewitinoff test described by Wohler in the Journal of the American Chemical Society, vol. 48, page 3181 (1927). Illustrative classes of compounds which contain at least one active hydrogen include, for instance, alcohols, amines, carboxylic acids, phenols, ureas, urethanes, hydrazines, Water, ammonia, hydrogen sulfide, imines, thioureas, sulfimides, amides, thiols, amino alcohols, sulfonamides, hydrazones, semicarbazones, oximes, hydroxycarboxylic acids, aminocarboxylic acids, vinyl polymers which contain a plurality of pendant active hydrogen substituents such as hydroxyl or amino, and the like. In addition, the hydrogen substituent may be activated by proximity to a carbonyl group. The alctive hydrogen organic compounds represent a preferred c ass.

Illustrative of the aforesaid active hydrogen compounds are the hydroxyl-containing compounds, especially those which possess at least one alcoholic hydroxyl group and preferably at least two alcoholic hydroxyl groups. Typical compounds include, for instance, the monohydric alcohols such as methanol, ethanol, propanol, isopropanol, 1-butanol, allyl alcohol, Z-butanol, tert-butanol, 3-butanol, 1- pentanol, 3-pentanol, l-hexanol, hex 5 en 1 ol, 3-heptanol, 2-ethyl 1 hexanol, 4-nonanol, propargyl alcohol, benzyl alcohol, cyclohexanol, cyclopentanol, cycloheptanol, and trimethylcyclohexanol. Further alcohols contemplated include glycidol, 4-oxatetracyclo[6.2.1.0 ]undecan 9 01, and the monoesterified diols such as those prepared by the reaction of equimolar amounts of an organic monocarboxylic acid, its ester, or its halide, with a diol such as alkylene glycols, monoand polyether diols, monoand polyester diols, etc., e.g.,

O I ll EL 0 R'OH wherein RC is acyl and R is a divalent organic radical containing at least two carbon atoms in the divalent chain; the monoetheri fied diols such as those represented by the formula R OROH wherein R represents a monovalent organic radical such as a hydrocarbyl or oxahydrocarbyl radical and R has the aforesaid value; the mono-01s produced by the partial esterification reaction of a polyol containing at least three hydroxyl groups, e.g., glycerine, with a stoichiometric deficiency of an organic monocarboxylic acid, its ester, or acyl halide; and the like. The aforesaid reactions are well documented in the literature.

Polyhydric alcohols can be exemplified by polyols of the formula HOROH wherein R is a divalent hydrocarbyl radical and preferably a substituted or unsubstituted alkylene radical, the aforesaid formula hereinafter being referred to as alkylene glycols; or by the formula HOROH wherein R' is a substituted or unsubstituted (alkyleneoxy), alkylene radical with n being at least one, this latter formula hereinafter being referred to as polyether glycols. The variables R and R have at least two carbon atoms in the linear chain, and the substituents or pendant groups on these variables can be, for example, lower alkyl, halo, lower alkoxy, etc., such as methyl, ethyl, n-propyl, isopropyl, chloro, methoxy, ethoxy, and the like. Illustrative alkylene glycols and polyether glycols include ethylene glycol, propylene glycol; butylene glycol; 2,2 dimethyl 1,3 propanediol; 2,2 diethyl 1,3 propanediol; 3 methyl 1,5 pentanediol; 2 butene-1,4- diol; the polyoxyalkylene glycols such as diethylene glycol, dipropylene glycol, dibutylene glycol, polyoxytetramethylene glycol, and the like; the mixed monoand polyoxyalkylene glycols such as the monoand polyoxyethyleneoxypropylene glycols, the monoand polyoxyethyleneoxybutylene glycols, and the like; polydioxolane and polyformals prepared by reacting formaldehyde with other glycols or mixtures of glycols, such as tetramethylene glycol and pentamethylene glycol; and the like. Other polyols include the N-methyland N-ethyl-diethanolamines; 4,4 methylenebiscyclohexanol; 4,4 isopropylidenebiscyclohexanol; butyne 1,4 diol; the ortho-, meta-, and para-xylene glycols; the hydroxymethyl substituted phenethyl alcohols; the ortho-, meta-, and para-hydroxymethylphenylpropanols; the various phenylenediethanols, the various phenylenedipropanols, the various heterocyclic diols such as 1,4 piperazinediethanol; and the like. The polyhydroxy-containing esterification products which range from liquid to non-crosslinked solids, i.e., solids which are soluble in many of the more common inert normally liquid organic media, and which are prepared by the reaction of monocarboxylic acids and/or polycarboxylic acids, their anhydrides, their esters, or their halides, with a stoichiometric excess of a polyol such as the various diols, triols, etc.; illustrated previously, are highly preferred. The aforesaid polyhydroxyl-containing esterification products will hereinafter be referred to as polyester polyols. Those polyester polyols which contain two alcoholic hydroxyl groups will hereinafter be termed polyester diols. Illustrative of the polycarboxylic acids which can be employed to prepare the polyester polyols preferably include the dicarboxylic acids, tricarboxylic acids, etc., such as maleic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, chlorendic acid, 1,2,4 butanetricarboxylic acid, phthalic acid, etc. This esterification reaction is well documented in the literature.

Higher functional alcohols suitable for reaction with the novel polyisocyanates, e.g., the novel diisocyanates and the novel polyisocyanato-containing polymers, include the triols such as glycerol, 1,1,1 trimethylolpropane, 1,2,4- butanetriol, 1,2,6 hexanetriol, triethanolamine, triisopropanolamine, and the like; the tetrols such as erythritol, pentaerythritol, N,N,N,N'-tetrakis(2 hydroxyethyl)ethylenediamine, N,N,N,N'-tetrakis(2 hydroxypropyl)ethylenediamine, and the like; the pentols; the hexols such as dipentaerythritol, sorbitol, and the like; the alkyl glycosides such as the methyl glucosides; the carbohydrates such as glucose, sucrose, starch, cellulose, and the like.

Other suitable hydroxyl-containing compounds include the monoand the polyoxyalkylated derivatives of monoand polyfunctional compounds having at least one reactive hydrogen atom. These functional compounds may contain primary or secondary hydroxyls, phenolic hydroxyls, primary or secondary amino groups, amide, hydrazine, guanido, ureido, mercapto, sulfino, sulfonamido, or carboxyl groups. They can be obtained by reacting, (1) monohydric compounds such as aliphatic and cycloaliphatic alcohols, e.g., alkanol, alkenol, methanol, ethanol, allyl 19 alcohol, 3-buten-l-ol, 2-ethylhexanol, etc.; diols of the class L HO \R/n OH and H ORO/H wherein R is alkylene of 2 to 4 carbon atoms and wherein n equals 1 to such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, and the like; tln'odiethanol; the xylenediols, 4,4'-methylenediphenol, 4,4'-iso propylidenediphenol, resorcinol; and the like; the mercapto alcohols such as mercaptoethanol; the di-basic acids such as maleic, succinic, glutaric, adipic, pimelic, sebacic, phthalic, tetrahydrophthalic, and hexahydrophthalic acids; phosphorous acids, phosphoric acids; the aliphatic, aromatic, and cycloaliphatic primary monoamines, like methylamine, ethylamine, propylamine, butylamine, aniline, and cyclohexylamine; the secondary diamines like N,N'- dimethylethylenediamine; and the amino alcohols containing a secondary amino group such as N-methylethanolamine; with (2) vicinal monoepoxides as exemplified by ethylene oxide, 1,2-epoxypropane, 1,2-epoxybutane, 2,3- epoxybutane, isobutylene oxide, butadiene monoxide, allyl glycidyl ether, 1,2-epoxyoctene-7, styrene oxide, and mixtures thereof.

Further examples of polyols are the polyoxyalkylated derivatives of polyfunctional compounds having three or more reactive hydrogen atoms such as, for example, the reaction products (adducts) of 1,1,1-trimethylolpropane with a lower vicinal-epoxyalkane, e.g., ethylene oxide, propylene oxide, butylene oxide, and mixtures thereof, in accordance with the reaction:

OHzOH CH3CH2-CCH2OH CHz-CHZ (31120]?! 0 CH(CH2CHO);H

CHsCHz-C-CHzO (CHZCHzO) yH CHzO (CHaCHzOhH wherein x+y+z equals 3 to 45, and more.

In addition to the polyoxyalkylated derivatives of 1,1,1- trimethylolpropane, the following illustrative compounds are likewise suitable: 1,1,l-trimethylolethane, glycerol; 1, 2,4-butanetriol; 1,2,6-hexanetriol; erythritol, pentaerythritol; sorbitol; the alkyl glycosides such as the methyl glucosides; glucose; sucrose; the diamines of the general formula H N(CH ),,NH where n equals 2 to 12; 2- (methylamino)ethylarnine; the various phenyleneand toluenediamines; benzidine; 3,3'-dimethyl-4,4'biphenyldiamine; 4,4'-methylenedianiline; 4,4,4"-methylidynetrianiline, the cycloaliphatic diamines such as 2,4-cyclohexanediamine, and the like; the amino alcohols of the general formula HO(CH NI-I where n equals 2 to 10; the polyalkylenepolyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and the like; the polycarboxylic acids such as citric acid, aconitic acid, mellitic acid, pyromellitic acid, and the like; and polyfunctional inorganic acids like phosphoric acid. The aforesaid polyfunctional polyoxyalkylated compounds will be referred to hereinafter as polyoxyalkylated polyols. The polyoxyalkylated polyols which contain two alcoholic hydroxyl groups will be termed polyoxyalkylated diols whereas those which contain a sole alcoholic hydroxyl group will be referred to as polyoxyalkylated mono-01s.

Illustrative amino-containing compounds which are contemplated are those which contain at least one primary amino group (--NH or secondary amino group NHR wherein R is hydrocarbyl such as alkyl, aryl, cycloalkyl, alkaryl, aralkyl, etc.), or mixtures of such groups. Preferred amino-containing compounds are those which contain at least two of the above groups. Illustrative of the amino-containing compounds include the aliphatic amines such as the alkylarnines, e.g., the methyl-, ethyl-, n-propyl-, isopropyl-, n-butyl-, sec-butyl-, isobutyl-, tert-butyl-, namyl-, n-hexyl-, and 2-ethylhexylamines, as well as the corresponding dialkylamines; the aromatic amines such as aniline, ortho-toluidine, meta-toluidine, and the like; the cycloaliphatic amines such as cyclohexylamine, dicyclohexylamine, and the like; the heterocyclic amines such as pyrrolidine, piperidine, morpholine, and the like; the various in aliphatic diamines of the general formula monosecondary diamines of the general formula RNH(CH NH and disecondary diamines of the general formula R"NH(CH ),,NHR"

where 1: equals 2 to 10, and more, and where R" is hydrocarbyl such as alkyl, aryl, aralkyl, alkaryl, or cycloalkyl; the etheric diamines of the formula wherein n is an integer of 2 to 10, and wherein R is alkylene or oxaalkylene of 2 to 10 carbon atoms; the aromatic diamines such as the cycloaliphatic diamines such as 1,4-cyclohexanediamine, 4,4'-methylenebiscyclohexylamine, and 4,4'-isopropylidenebiscyclohexylamine; and

the heterocyclic amines such as piperazine, 2,5-dimethylpiperazine, l,4-bis(3-aminopropyl)piperazine, and the like.

Illustrative of the higher functional amino-containing compounds which can be employed include, for example, higher polyalkylenepolyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, dipropylenetriamine, tripropylenetetrarnine, tetrapropylenepentamine, and the like; 1,2,5 benzenetriamine; toluene-2,4,6 triamine; 4,4',4"-methylidynet1ianiline, and the like; the polyamines obtained by interaction of aromatic monoamines with formaldehyde or other aldehydes, for example:

I R OCHz@-NH2 R and other reaction products of the above general type, where R is, for example, hydrogen or alkyl.

Illustrative of the carboxyl-containing compounds include those organic compounds which contain at least one carboxyl group (COOH) as exemplified by the monocarboxyl-containing compounds such as alkanoic acids; the cycloalkanecarboxylic acids; the monoesterified dicarboxlic acids, e.g.

if u ROCRCOH wherein R is an organic radical such as oxahydrocarbyl, hydrocarbyl, etc., and R is the divalent residue of a dicarboxylic acid after removal of the two dicarboxylic groups; the polycarboxylic acids, e.g., the aliphatic, cycloaliphatic, and aromatic dicarboxylic acids; and the like. Specific examples include propionic acid, butyric acid, valeric acid, dodecanoic acid, acrylic acid, cyclohexanecarboxylic acid, the mono-Z-ethylhexyl ester of adipic acid, succinic acid, maleic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, chlorendic acid, 4,4'-oxydibutyric acid, 5,'-oxydivaleric acid, 6,6-oxydihexanoic acid, 4,4'-thiodibutyric acid, 5,5-thiodivaleric acid, 6,6-thiodihexanoic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, tetrachlorophthalic acids, 1,5-naphthoic acid, 2,7-naphthoic acid, 2,6-naphthoic acid, 3,3'-methylenedibenzoic acid, 4,4'-(ethylenedioxy)dibenzoic acid, 4,4-biphenyldicarboxylic acid, 4,4'-sulfonyldibenzoic acid, 4,4'-oxydibenzoic acid, the various tetrahydrophthalic acids, the various hexahydrophthalic acids, tricarballylic acid, aconitic acid, citric acid, hemimellitic acid, trimellitic acid, trimesic acid, pyromellitic acid, l,2,3,4-butanetetracarboxylic acid, and the like. The polycarboxyl-containing esterification products which range from liquid to non-crosslinked solids and which are prepared by the reaction of polycarboxylic acids, their anhydride, their esters, or their halides, with a stoichiometric deficiency of a polyol such as diols, triols, etc., can also be employed. These polycarboxyl-containing esterification products will hereinafter be referred to as polycarboxy polyesters.

Compounds which contain at least two different groups of the class of amino (primary or secondary), carboxyl, and hydroxyl, and preferably those which contain at least one amino group and at least one hydroxyl group, can be exemplified by the hydroxycarboxylic acids, the aminocarboxylic acids, the amino alcohols, and the like. Illustrative examples include Z-hydroxypropionic acid, 6-hydroxycaproic acid, ll-hydroxyundecanoic acid, salicylic acid, para-hydroxybenzoic acid, beta-alanine, 6- aminocaproic acid, 7-aminoheptanaoic acid, ll-aminoundecanoic acid, para-aminobenzoic acid, and the like; the amino alcohols of the general formula HO(CH ),,NH where n equals 2 to 10; other hydroxyalkylamines such as N-methylethanolamine, isopropanolamine, N-methylisopropanolamine, and the like; the aromatic amino alcohols like para-amino-phenethyl alcohol, para-aminoalpha-methylbenzyl alcohol, and the like; the various cycloaliphatic amino alcohols such as 4-aminocyclohexanol, and the like; the higher functional amino alcohols having a total of at least three hydroxy and primary or secondary amino groups such as the dihydroxyalkylamines, e.g., diethanolamine, diisopropanol amine, and the like; 2-(2-amino ethylamino)ethanol; 2-amino-2(hydroxymethyl)-l,3-propanediol; and the like.

The initiated lactone polyesters which contain free hydroxyl group(s) and/or carboxyl group(s) represent extremely preferred active hydrogen containing compounds. These initiated lactone polyesters are formed by reacting, at an elevated temperature, for example, at a temperature of from about 50 C. to about 250 C., an admixture containing a lactone and an organic initiator; said lactone being in molar excess with relation to said initiator; said lactone having from six to eight carbon atoms in the lactone ring and at least one hydrogen substituent on the carbon atom which is attached to the oxy group in said ring; said organic initiator having at least one reactive hydrogen substituent preferably of the group of hydroxyl, primary amino, secondary amino,

carboxyl, and mixtures thereof, each of said reactive hydrogen substituents being capable of opening the lactone ring whereby said lactone is added to said initator as a substantially linear group thereto; said initiated lactone polyesters possessing, on the average, at least two of said linear groups, each of said linear groups having a terminal oxy group at one end, a carbonyl group at the other end, and an intermediate chain of from five to seven carbon atoms which has at least one hydrogen substituent on the carbon atom in said intermediate chain that is attached to said terminal oxy group. The aforesaid polyesters will hereinafter be referred to, in the generic sense, as initiated lactone polyesters which term will also include the various copolymers such as lactone copolyesters, lactone polyester/polycarbonates, lactone polyester/polyethers, lactone polyester/polyether/polycarbonates, lactone polyester/polyesters, etc. These initiated lactone polyesters will contain at least one hydroxyl group and/or at least one carboxyl group depending, of course, on the initiator and reactants employed. Those initiated lactone polyesters which contain at least three alcoholic hydroxyl groups will be referred to as initated lactone polyester polyols; those with two alcoholic hydroxyl groups will be termed initiated lactone polyester diols. On the other hand, the initiated lactone polyesters which contain at least two carboxyl groups will be referred to as initiated polycarboxy lactone polyesters.

The preparation of the aforesaid hydroxyl-containing and/or carboxyl-containing initiated lactone polyesters can be effected in the absence or presence of an ester interchange catalyst to give initiated lactone polyesters of widely varying and readily controllable molecular weights without forming water of condensation. These lactone polyesters so obtained are characterized by the presence of recurring linear lactone units, that is, carbonylalkyleneoxy wherein x is from 4 to 6, and wherein the R variables have the values set out in the next paragraph.

The lactone used in the preparation of the initiated lactone polyesters may be any lactone, or combination of lactones, having at least six carbon atoms, for example, from six to eight carbon atoms, in the ring and at least one hydrogen substituent on the carbon atom which is attached to the oxy group in said ring. In one aspect, the lactone used as starting material can be represented by the general formula:

in which n is at least four, for example, from four to six, at least n+2 Rs are hydrogen, and the remaining Rs are substituents selected from the group consisting of hydrogen, alkyl, cycloalkyl, alkoxy and single ring aromatic hydrocarbon radicals. Lactones having greater number of substituents other than hydrogen on the ring, and lactones having four carbon atoms in the ring, are considered unsuitable because of the tendency that polymers thereof have to revert to the monomer, particularly at elevated temperature.

The lactones which are preferred in the preparation of the hydroxyl-containing and/ or carboxyl-containing initiated lactone polyesters are the epsilon-caprolactones having the general formula:

wherein at least six of the R variables are hydrogen and the remainder are hydrogen, alkyl, cycloalkyl, alkoxy, or single ring aromatic hydrocarbon radicals, none of the substituents contain more than about twelve carbon atoms, and the total number of carbon atoms in the substituents on the lactone ring does not exceed about twelve.

Among the substituted epsilon-caprolactones considered most suitable are the various monoalkyl epsiloncaprolactones such as the monomethyl-, monoethyl-, monopropyl-, monoisopropyl-, etc. to monododecyl epsiln-caprolactones; dialkyl epsilon-caprolactones in which the two alkyl groups are substituted on the same or different carbon atoms, but not both on the epsilon carbon atom; trialkyl epsilon-caprolactones in which two or three carbon atoms in the lactone ring are substituted, so long as the epsilon carbon atom is not disubstituted; alkoxy epsilon-caprolactones such as methoxy and ethoxy epsilon-caprolactones; and cycloalkyl, aryl, and aralkyl epsilon-caprolactones such as cyclohexyl, phenyl and benzyl epsilon-caprolactones.

Lactones having more than six carbon atoms in the ring, e.g., zeta-enantholactone and eta-caprylolactone can be employed as starting material. Mixtures comprising the C to C lactones illustrated previously, with/ without, for instance, the alpha, alpha-disubstituted-beta-propiolactones, e.g., alpha, alpha dimethyl beta propiolactone, alpha, alpha dichloromethyl beta propiolactone, etc.; with/without, for instance, oxirane compounds, e.g., ethylene oxide, propylene oxide, etc.; with/Without, for instance, a cyclic carbonate, e.g., 4,4-dimethyl-2,6-dioxacyclohexanone, etc; are also contemplated.

Among the organic initiators that can be employed to prepare the initiated lactone polyesters include the carboxyl-containing, hydroxyl-containing, and/or amino-containing compounds illustrated previously, e.g., those compounds which have at least one reactive hydrogen substituent as determined according to the Zerewitinoff method.

The initiator is believed to open the lactone ring to produce an ester or amide having one or more terminal groups that are capable of opening further lactone rings and thereby adding more and more lactone units to the growing molecule. Thus, for example, the polymerization of epsilon-caprolactone initiated with an amino alcohol is believed to take place primarily as follows:

1:1{0(omniipoR Nmb empower wherein R (of the initiator and the resulting initiated lactone polyester product) is an organic radical such as an aliphatic, cycloaliphatic, aromatic, or heterocyclic radical, and wherein a=b+c.

The reaction of a carboxyl-containing initiator with epsilon-caprolactone is believed to proceed as follows:

It will be appreciated from the preceding illustrative equations that where a plurality of lactone units are linked together, such linkage is effected by monovalently bonding the oxy (O) moiety of one unit to the carbonyl moiety of an adjacent unit. The terminal lactone unit will have a terminal hydroxyl or carboxyl end group depending, of course, on the initiator employed.

The preparation of the initiated lactone polyester can be carried out in the absence of a catalyst though it is preferred to efiect the reaction in the presence of an ester exchange catalyst. The organic titanium compounds that are especially suitable as catalysts include the tetraalkyl titanates such as tetraisopropyl titanate and tetrabutyl titanate. Additional preferred catalysts include, by way of further examples, the stannous diacylates and stannic tetraacylates such as stannous dioctanoate and stannic tetraoctanoate. The tin compounds, the organic salts of lead and the organic salts of manganese which are described in US. 2,890,208 as well as the metal chelates and metal acylates disclosed in U.S. 2,878,236 also represent further desirable catalysts which can be employed. The disclosures of the aforesaid patents are incorporated by reference into this specification.

The catalysts are employed in catalytically significant concentration. In general, a catalyst concentration in the range of from about 0.0001 and lower, to about 3, and higher, weight percent, based on the Weight of total monomeric feed, is suitable. The lactone polymerization reaction is conducted at an elevated temperature. In general, a temperature in the range of from about 50 C., and lower, to about 250 C. is suitable; a range from about C. to about 200 C. is preferred. The reaction time can vary from several minutes to several days depending upon the variables illustrated immediately above. By employing a catalyst, especially the more preferred catalysts, a feasible reaction period would be about a few minutes to about 10 hours, and longer.

The polymerization reaction preferably is initiated in the liquid phase. It is desirable to effect the polymerization reaction under an inert atmosphere, e.g., nitrogen.

The preparation of the lactone polyesters via the preceding illustrative methods has the advantage of permitting accurate control over the average molecular weight of the lactone polyester products and further of promoting the formation of a substantially homogeneous lactone polyester in which the molecular weights of the individual molecules are reasonably close to the average molecular weight, that is, a narrow molecular weight distribution is obtained. This control is accomplished by preselecting the molar proportions of lactone and initiator in a manner that will readily be appreciated by those skilled in the art. Thus, for example, if it is desired to form a lactone polyester in which the average molecular weight is approximately fifteen times the molecular weight of the initial lactone, the molar proportions of lactone and initiator utilized in the polymerization reaction are fixed at approximately 15:1 inasmuch as it is to be ex pected that on the average there will be added to each molecule of initiator approximately fifteen lactone molecules.

The initiated lactone polyesters which are contemplated have average molecular weights as low as 300 to as high as about 7000, and even higher still to about 9000. With vinyl polymers containing a plurality of active hydrogen substituents, e.g., hydroxyl, amino, etc., as initiators, the average molecular weight of the initiated lactone polyesters can easily go as high as 14,000, and higher. Generally, however, the average molecular weight of the initiated lactone polyester is from about 300 to about 9000, preferably from 600 to about 5000.

As intimated previously, also Within the term and the scope of the initiated lactone polyesters are those in which the linear lactone units need not necessarily be connected directly to one another. This is readily accomplished, for example, by reacting lactone(s) with combinations of initiators such as dibasic acid(s) plus glycol( s), diamine(s) or amino alcohol(s) such as those exemplified previously. This reaction can be efiected at an elevated temperature, e.g., about 100 C. to about 200 C., with all the reactants present, or the reaction of the dibasic acid with the glycol, diamine, or amino alcohol can be accomplished first, and then the resulting amino, hy

25 droxyl-, or carboxyl-containing products (depending on the reactants and the concentration of same) can be reacted with the lactone to yield hydroxyl-terminated and/ or carboxyl-terrninated initiated lactone polyesters. Moreover, as also indicated previously, the term and the scope of the hydroxyl-and/or carboxyl-containing initiated lactone polyesters includes the oxyalkylene-carboxyalkylenes such as described in US. Pat. No. 2,962,524 which are incorporated by reference into this disclosure. In addition the term and scope of the hydroxyl-containing initiated lactone polyesters also includes the reaction of an admixture comprising a C -C lactone(s), a cyclic carbonate( s), and an initiator having at least one group, preferably at least two groups, of the class of hydroxyl, pri mary amino, or secondary amino, or mixtures thereof, under the operative conditions discussed above. Exemplary cyclic carbonates include 4,4-dimethyl-2,6-dioxacyclohexanone, 4,4-dichloromethyl-2,6-dioxacyclohexanone, 4,4-dicyanomethyl-2,-dioxacyclohexanone, 4,4-diethyl-2,6-dioxacyclohexanone, 4,4 dimethoxymethyl-2,6-dioxacyclohexanone; and the like. Consequently, where a mixture of linear lactone units (i.e.,

o(oRi),oHRo

units which are properly termed carbonylalkyleneoxy) and linear carbonate units. (i.e.,

o i 3oRo units which can be termed carbonyloxyalkyleneoxy) are contained in the polymer chain or backbone, the carbonyl moiety of one linear unit will be monovalently bonded to the oxy moiety of a second linear unit. The oxy moiety of a terminal linear unit will be bonded to a hydrogen substituent to thus form a hydroxyl end group. Moreover, the point of attachment of the initiator and a linear unit (lactone or carbonate) will be between the carbonyl moiety of said unit and the functional group (hydroxyl or amino) of said initiator sans the active hydrogen substituent of said group.

The preferred initiated lactone polyesters include those which contain at least tbout 50 mol percent of carbonylpentamethyleneoxy units therein and which possess an average molecular weight of from about 500 to about 5000, particularly from about 600 to about 4000. The remaining portion of the molecule can be comprised of in addition to the initiator, essentially linear units derived from cyclic carbonate especially those illustrated previously; an oxirane compound especially ethylene oxide, propylene oxide, and/ or butylene oxide; a monoand/or polyalkyl-substituted epsilon-caprolactone especially the monoand/or polymethyl and/or ethylsubstituted epsilon-caprolactones; and/ or an alpha, alphadisubstituted-beta-propiolactone especially those exemplified previously. The so-called initiated lactone homopolyesters derived from reacting epsilon-caprolactone with an initiator are likewise included within the preferred lactone polyesters. The initiated lactone polyester polyols, and in particular, the substantially linear initiated lactone polyester diols, are exceptionally preferred.

If desired, various compounds can be employed as catalysts in the isocyanato/active hydrogen reactions. Compounds which are oftentimes useful in catalyzing said isocyanato-active hydrogen reactions include the tertiary amines, phosphines, and various organic metallic compounds in which the metal can be bonded to carbon and/ or other atoms such as oxygen, sulfur, nitrogen, halo, hydrogen, and phosphorus. The metal moiety of the organic metallic compounds can be, among others, tin, titanium,

lead, potassium, sodium, arsenic, antimony, bismuth, manganese, iron, cobalt, nickel, and zinc. Of those which deserve special mention are the organic metallic compounds which contain at least one oxygen to metal bond and/or at least one carbon to metal bond, especially wherein the metal moiety is tin, lead, bismuth, arsenic, or antimony. The tertiary amines, the organic tin compounds (which includes the organotin compounds), and the organic lead compounds are eminently preferred. Preferred subclasses of organic metallic compounds include the acylates, particularly the alkanoates, and alkoxides of Sn(II), Sn(IV), Pb(II), Ti(IV), Zn(IV), Co(II), Mn(II), Fe(III), Ni(II), K, and Na. An additional subclass which is extremely useful is the dialkyltin dialkanoates.

Inorganic metallic compounds such as the hydroxides, oxides, halides, and carbonates of metals such as the alkali metals, the alkaline earth metals, iron, zinc, and tin are also suitable.

Specific catalysts include, by Way of illustrations, 1,4- diazabicyclo[2.2.2]octane, N,N,N',N' tetramethyl 1,3- butanediamine, bis[2 (N,N dimethylamino)ethyl] ether, bis[2 (N,N dimethylamino) l-methylethyl] ether, N- methylmorpholine, sodium acetate, potassium laurate, stannous octanoate, stannous oleate, lead octanoate, tetrabutyl titanate, ferric acetylacetonate, cobalt naphthenate, tetramethyltin, tributyltin chloride, tributyltin hydride, trimethyltin hydroxide, dibutyltin oxide, dibutyltin dioctanoate, dibutyltin dilaurate, butyltin trichloride, triethylstibine oxide, potassium hydroxide, sodium carbonate, magnesium oxide, stannous chloride, stannic chloride, bismuth nitrate. Other catalysts include those set forth in Part IV. Kinetics and Catalysis of Reactions of Saunders, et al. Polyurethanes: Chemistry and TechnologyPart I. Chemistry, Interscience Publishers, which is incorporated by reference into this disclosure. In many instances, it is particularly preferred to employ combinations of catalysts such as, for example, a tertiary amine plus an organic tin compound.

The isocyanato-reactive hydrogen reactions can be conducted over a wide temperature range. In general, a temperature range of from about 0 to about 250 C. can be employed. To a significant degree, the choice of the reactants and catalyst, if any, influences the reaction temperature. Of course, sterically hindered novel diisocyanates or active hydrogen compounds will retard or inhibit the reaction. Thus, for example, the reaction involving iso cyanato with primary amino or secondary amino can be effected from about 0 C. to about 250 C. whereas the isocyanato-phenolic hydroxyl reaction is more suitable conducted from about 30 C. to about C. Reactions involving primary alcoholic hydroxyl, secondary alcoholic hydroxyl, or carboxyl with isocyanato are effectively conducted from about 20 C. to about 250 C. The upper limit of the reaction temperature is selected on the basis of the thermal stability of the reaction products and of the reactants whereas the lower limit is influenced, to a significant degree, by the rate of reaction.

The time of reaction may vary from a few minutes to several days, and longer, depending upon the reaction temperature, the identity of the particular active hydrogen compound and diisocyanate as well as upon the absence or presence of an accelerator or retarder and the identity thereof, and other factors. In general the reaction is conducted for a period of time which is at least sufiicient to provide the addition or attachment of the active hydrogen from the active hydrogen compound to the isocyanato nitrogen of the novel diisocyanate. The remainder of the active hydrogen compound becomes bonded to the carbonyl carbon unless decarboxylation or further reaction occurs. The following equation illustrates the reaction involved.

wherein HZ represents the active hydrogen compound. Thus, by way of illustrations the reaction of isocyanato (NCO) With (a) hydroxyl (OH) results in the i NHCO group; (b) primary amino (NH results in the NH NH group; (c) secondary amino (NHR) results in the o -NHhNR- group (d) thiol (SH) results in the o NH c'1 sgroup; (e) carboxyl (COOH) can be considered to result in the intermediate [-NHii G i-1 which decarboxylates to the l! NHC- p; ureylene ll (NHCNH--) results in the H 1] lTION- O=C-NH- group (biuret); (g) amido ii-NHR results in the ONC NH- group (carbonylurea); (h) urethane o (NHICII o-) results in the group (allophanate); (i) Water (HOH) can be considered to result in the intermediate which decarboxylates to the NH group; and the like. Most desirably, conditions are adjusted so as to achieve a practical and commercially acceptable reaction rate depending, to a significant degree, on the end use application which is contemplated. In many instances, a reaction period of less than a few hours is oftentimes sufficient for the intended use.

The isocyanato-reactive hydrogen reactions, in many, instances, are preferably accomplished in the presence of a catalytically significant quantity of one or more of the catalysts illustrated previously. In general, a catalyst concentration in the range of from about 0.001 weight percent, and lower, to about 2 weight percent, and higher, based on the total weight of the reactants, has been observed to be useful.

The concentration of the reactants can be varied over a wide range. Thus, for example, one can employ the active hydrogen compound in such relative amounts that there is provided as low as about 0.1 equivalent (group) of active hydrogen, and lower, per equivalent (group) of isocyanato. In general, about 0.2 and oftentimes about 0.25 equivalent of active hydrogen represent more suitable lower limits. The upper limit can be as high as about 7 equivalents of active hydrogen, and higher, per equivalent of isocyanato. However, for many applications, a desirable upper limit is about 3.5 equivalents of active hydrogen per equivalent of isocyanato. When employing bifunctional compounds (those which contain two active hydrogen substituents such as hydroxyl, carboxyl, primary amino, secondary amino, etc.), a suitable concentration would be from about 0.25 to about 3 equivalents of active hydrogen substituent from the bifunctional compound per equivalent of isocyanato from the isocyanate. It is readily apparent that depending upon the choice and functionality of the active hydrogen compounds(s), the choice of the polyisocyanate(s), the proportions of the reactants, etc., there can be obtained a myriad of novel compounds and products which range from the liquid state to solids which can be fusible solids, thermoplastic solids, partially cured to essentially completely cured, thermoset solids, etc. The novel liquid to non-crosslinked solid compositions contain a plurality of polymerizable ethylenic bonds which serve as vinyl polymerization sites with vinyl monomers such as those illustrated previously, e.g., styrene, butadiene, vinyl chloride, etc., under the operative conditions noted supra.

A class of novel compounds which deserve special mention are those which contain the grouping therein. These compounds are characterized as follows:

ii 1 11 ll zoNnnoornoonNnoz wherein R and R have the values set out in Formula 1 supra, and wherein Z is an abbreviated form for the monofunctional active organic compound sans the active hydrogen atom. Illustrative Z radicals include those which result from the reaction of, for example. stoichiometric quantities of the novel diisocyanates of Formula I supra with monofunctional active organic compounds as illustrated by primary amines, secondary amines, primary alcohols, secondary alcohols, phenols, primary thiols, secondary thiols, imines, amides, ureas, etc. The scope of Z is readily apparent from the description re the active hydrogen compounds as Well as from a consideration of 'Equation X supra. Moreover, by reacting equimolar amounts of the diisocyanates of Formula I with the aforeillustrated monofunctional active organic compounds, there can be obtained monoisocyanates of the formula:

0 I] H II OCNROCRiCORNHCZ A further class of polymeric products which deserve to be highlighted are those novel polymers which are characterized by Unit XII below:

(XII) wherein R", R, R, and m have the values (including the provisos) set out in Unit IX supra, and wherein Z is adequately described in the discussion re Formula XI supra.

A still further class of polymeric products which should 29 be exemplified by illustration include the novel polymers which are characterized by Unit XIIA below:

(XIIA) f l i ii i ii RNH ZCHNROC \R/m \R/m Oz wherein R", R, R, R m, and x have the meanings set out in Unit IXA, and wherein Z has the value set out in Unit XI supra.

Highly desirable subclasses of novel polymeric products are those which are characterized by the following Units XI-IB, XIIC, and XIID below:

(XIIB) (H) wherein the variables R, R R, m, and x have the values noted in Unit IXA supra: (XIIC) TI) (1? CORNHCZ CH(lJH CORNHCZ WhereinR is an alkylene radical whcih from 2 to 12 carbon atoms; (XIID) WI) (1? CORNHCZ -CHCH(R1)X CORNHCZ wherein R has the broad and preferred values set out in Unit IXC supra, and wherein R and x have the values noted in Unit IXA supra. The variable Z in the aforesaid units is described in Unit XI supra.

The novel polymeric products contain at least one of the units designated as Units XII through XIID, andun general, these products contain a plurality of said units, e. g., upwards to 200, and more.

A useful subarea of polymeric products result from the reaction of the novel telomers of the bis[omega isocyanato-(C -C alkyl)] fumarates, the citraconates, and the itaconates, with a monofunctional active organic compound such as those illustrated previously. Those relative low molecular weight polymeric products characterized by at least two and upwards to about 20, preferably 3 to about 10, of the units set forth below are suitable for many useful applications:

preferably contains It is pointed out that the proviso noted in Formula I applies to Units IX through IXF, Formulas XI and XIA, and Units XII through XI IF. It is also pointed out that the novel polymeric products which are characterized by 0 tion of an admixture comprising the partially blocked isocyanate of Formula XIA with/without the diisocyanate of Formula -I, with/without the blocked isocyanate of Formula XI, and with/without an ethylenically unsaturated organic compound.

A particular desirable class of novel polyurethane diols which are contemplated within the scope of the teachings of this specification are those which result from the reaction of a dihydroxy compound such as those illustrated previously, with a molar deficiency, i.e., a stoichiometric deficiency, of the novel diisocyanates which fall within Formula I supra. The highly preferred dihydroxy compounds are the alkylene glycols, the polyether glycols, the polyoxyalkylated diols, the polyester diols, and the initiated lactone polyester diols, especially those dihydroxy compounds which have average molecular weights as low as about '60 and as high as about 7000, and higher. A preferred average molecular weight range is from about 300 to about 5000. The initiated lactone polyester diols which have an average molecular weight of from about 600 to about 4000 are eminently preferred since within this molecular weight range there can be prepared, for example, polyurethane products such as cast resins, thermoplastic products, and elastic fibers which exhibit outstanding performance characteristics. Equation XIII below illustrates the linear extension reaction involved:

(XIII) HOAOH deficient Q(NCO)2 O O 7 HH wherein HO-AOH is an abbreviated representation of the organic dihydroxy compounds, the variable A being an organic divalent aliphatic radical such as those illustrated previously; wherein Q(NCO) is an abbreviated representation for the novel diisocyanates encompassed Within the scope of Formula I supra, the variable Q representing the divalent unit 0 O Ro( 3R1( ioR the R and R variables of said unit having the assigned values of Formula I supra; and wherein n is a number having an average value of at least one.

It will be noted from Equation XIII that the degree of linear extension is realistically controlled by the amount of the reactants employed. If the proportions of diol and diisocyanate are chosen so that the number of reactive hydroxyl groups on the diol are equal to the number of reactive isocyanate groups on the diisocyanate, then rel atively long, high molecular weight chains can be formed. In general, one can employ such relative amounts so that there is provided slightly greater than one equivalent of hydroxyl group from the diol per equivalent of isocyanato group from the diisocyanate. It is desirable, however, to employ amounts of diol and organic diisocyanate (in Equation XIII) so that there is provided a ratio of from about 1.1 to about 2.2 equivalents, and higher, of hydroxyl group per equivalent of isocyanato group, and preferably from about 1.3 to about 2 equivalents of hydroxyl group per equivalent of isocyanato group.

It is to be understood that in lieu of the dihydroxy compounds employed in Equation XIII one can employ higher functional polyols such as the triols, tetrols, etc., and obtain novel polyurethane triols, tetrols, etc. In addition, admixtures of dihydroxy compounds, or dihydroxy (XIV) HOAOH excess Q,(NCO)2 II ll CNiQNHC OAO CNHlHQNCO Polyurethane Diisocyanate (Prepolymer) wherein all the variables of Equation XIV have the meanings set out in Equation XIII previously.

It will be noted from Equation XIV that the use of an excess of diisocyanate provides an efficient means of control over the degree of linear extension of the polyurethane molecule. If the proportions of diol and diisocyanate are chosen so that the number of reactive terminal hydroxyl groups on the diol are equal to the number of reactive isocyanate groups on the diisocyanate, as indicated previously, relatively long, high molecular weight chains would be formed. It is desirable, for many applications, to employ amounts of diisocyanate and diol (in Equation XIV) so that there is provided a ratio of greater than about one equivalent of diisocyanate per equivalent of diol, preferably from about 1.05 to about 7 equivalents, and higher, of diisocyanate per equivalent of diol, and preferably still from about 1.2 to about 4 equivalents of diisocyanate per equivalent of diol.

During and after preparation of the isocyanato-terminated reaction products it is oftentimes desirable to stabilize said reaction products by the addition of retarders to slow down subsequent further polymerization or less desirable side-reactions such as, for example, allophanate formation. Retarders may be added to the diisocyanate, diol, and/or the aforesaid reaction products. Illustrative of the retarders suitable for the diol-diisocyanate reaction are hydrochloricacid, sulfuric acid, phosphoric acid, boric acid, acetyl chloride, para-toluenesulfonyl chloride, phosphorous trichloride, phosphorous oxychloride, sulfuryl chloride, thionyl chloride, and sulfur dioxide.

In lieu of, or in conjunction with the dihydroxy reacts ants of Equation XIV, it is oftentimes desirable to employ higher functional polyols such as the triols, tetrols, etc., and obtain novel polyurethane triisocyanates, tetraisocyanates, etc.

Another particular desirable class of novel compounds which are contemplated are the novel polyurea diamines which are prepared via the reaction of a diamino com pound (which contain two groups from the class of primary amino, secondary amino, and mixtures thereof) as illustrated previously with a molar deficiency of the novel diisocyanates. Equation XV below illustrates this linear extension reaction involved:

drocarbon or azahydrocarbon radical, e.g., alkyl, aryl,

aralkyl azaalkyl, and the like; and D representing a divalent organic radical, e.g., a divalent aliphatic, alicyclic, aromatic, or heterocyclic radical), and wherein Q(NCO) and n have the meanings set forth in Equation XIII supra. In general, one can employ slightly greater than about one and upwards to about two, and higher, equivalents of amino group per equivalent of isocyanato group. In lieu of, or in conjunction with, the diamino reactants of Equation XV, it is oftentimes desirable to employ higher functional polya-mines such as the triamines, tetraamines, etc., and obtain novel polyurea triamines, polyurea tetraamines, etc.

On the other hand, the use of a molar excess of diisocyanate with relation to the diamino compound produces novel polyurea diisocyanates as illustrated by Equation XVI:

LtRl

Polyurea Diisocyanate In the reaction exemplified by Equation XVI supra, there can be employed slightly greater than about one and upwards to about 3, and higher, equivalents of isocyanato group per equivalent of amino group. Higher functional polyamines can be employed instead of, or admixed with, the diamines, to thus yield novel polyurea triisocyanates, polyurea tetraisocyanates, etc.

If desired, the preceding novel linear extension reactions can be carried out in the presence of essentially inert normally-liquid organic vehicles such as various organic solvents, depending upon the further application which may be intended for said reaction products.

In another aspect, the invention is directed to the prep aration of cast polyurethane systems. Highly useful rigid to flexible, polyurethane resins which can range from slightly crosslinked products to highly crosslinked products can be prepared by the novel diisocyanates of Formula I supra and/or the novel polyisocyanato-containing polymers exemplified by Units IX to IXF supra and/ or the polyurethane polyisocyanato reaction products discussed in the section re Equation XIV with a polyfunctional chain extender which contains at least two functional groups that are primary amino (NH secondary amino (NHR), hydroxyl (OH), or mixtures thereof. The polyisocyanate and polyfunctional chain extender are employed in such relative amounts that there is provided at least about one equivalent (group) of isocyanato (--NCO) from the polyisocyanate per equivalent (group) of functional group (hydroxyl and/or amino) from the polyfunctional compounds. When employing solely difunctional compounds as the chain extender(s), it is desirable to employ such relative amounts that result in greater than about one equivalent of NOO, e.g., at least about 1.02 equivalents of NCO, from the polyisocyanate per functional group from the difunctional compound. However, it is oftentimes highly satisfactory when employing polyfunctional chain extenders which contain 3 or more functional groups, alone or in admixture with difunctional chain extenders, to employ such relative amounts so that there is provided at least about one equivalent of NCO from the polyisocyanate per equivalent of functional group from the chain extender(s). Cast polyurethane resins having special utility as printing ink rollers, cast solid urethane industrial tires, mechanical goods such as seals, O-rings, gears, etc., ladies shoe heels, and the like, can be prepared from castable formulations which provide from about 1.02 to about 1.6 equivalents of NCO from the polyisocyanate per equivalent of functional group from the polyfunctional chain extender. Optimum properties result from the highly preferred castable formulations which provide from about 1.05 to about 1.4 equivalents of -NCO per equivalent of functional group.

It is further highly desirable that the aforesaid polyisocyanate be a prepolymer as defined in Equation XIV supra which has an average molecular weight of at least about 550 in the preparation of cast polyurethane resins. The upper limit can be as high as 8000 and higher. For many applications, practical molecular weight range is from about 750 to about 5000. It is observed that within the aforesaid molecular weight limits there can be produced cast polyurethane resins which vary from extremely soft flexible products to relatively hard plastic products. Prepolyrners which result from the reaction of diisocyanate and the initiated lactone polyester polyols are eminently suitable since cast resins which possess high performance characteristics can be obtained.

Among the polyfunctional chain extenders which can be employed in the castable formulations are those organic compounds exemplified previously which have two or more hydroxyl or amino (primary and secondary) groups including mixtures of such groups such as the polyols, (diols, triols, tetrols, etc.), the polyamines (diamines, triamines, etc.), amino alcohols, and the like. Among the polyfunctional chain extenders which deserve special mention because they result in especially useful cast polyurethane resins of high strength, high tear resistance, relatively low permanent set, good solvent resistance, and/ or excellent abrasion resistance can be listed the following: 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, quinitol, 1,4-bis(2-hydroxyethoxy)benzene, 4,4- bis (2-hydroxyethoxy)phenyl1isopropylidene, trimethylolpropane, triisopropanolamine, ethanolamine, p-aminophenylethyl alcohol, 2,4- and 2,6-toluenediamines, 3,3- dichloro-4,4-diphenylenediamine, and 4,4'-methylene bis- (o-chloroaniline) The preparation of the cast polyurethane products can take place over a wide temperature range, e.g., from about room temperature to about 200 C., and higher. The preferred temperature is in the range of from about 50 C. to about 150 C. A highly preferred temperature range is from about 60 C. to about 105 C. The upper limit of the reaction temperature, as indicated previously, is realistically controlled by the thermal stability of the reactants and reaction products whereas the lower limit is regulated, to a significant degree, by the reaction rate.

A valuable modification of the cast polyurethane aspect is the use of an admixture containing the polyols exemplified previously \m'th/without the novel polyurethane diols (of Equation XIII) plus the novel diisocyanates (of Formula I) instead of, or in conjunction with, the prepolymer (of Equation XIV). It is preferred that the previously exemplified polyols be substantially linear hydroxyl-terminated polymers. It is highly preferred that these polymers have an average molecular weight of at least about 60 and upwards to 6000, and higher, and preferably from about 300 to about 5000. The hydroxyl-terminated polymers which are eminently suitable include the alkylene glycols, the polyether glycols, the polyester diols, the polyoxyalkylated diols, and the initiated lactone polyester diols. In this modification, the ratios of the equivalents of NCO and the equivalents of functional groups are the same as set forth above. It is understood, of course, that these ratios will include all the -NCO groups and all the functional groups in the castable formulation regardless of the source. Thus, for example, if the formulation comprises novel polyurethane diol, novel diisocyanate, and alkane diol, one must take into consideration when computing the equivalents ratio of said formulation, the equivalents of -NCO from the diisocyanate with relation to the 34 sum of the equivalents of the hydroxyl groups from the polyurethane diol plus alkanediol.

A further desirable modification of the cast polyurethane aspect is directed to the partial or incomplete reaction of the cast formulation to thus produce a thermoplastic reaction product mass which contains unreacted or free isocyanate groups. The aforesaid thermoplastic mass is relatively stable or non-reactive at room temperature, e.g., about 20 C., but possesses the characteristic of being further cured as, for example, by curing same at an elevated temperature for a sufficient period of time. This curable, isocyanate-containing mass can be prepared by heating the cast formulation or system, e.g., to about C., and higher, and thereafter quenching the resulting partial reaction products (which contain a minor proportion of unreacted isocyanato groups) with an inert fluid in which said reaction products are insoluble, e.g., an inert normally liquid organic non-solvent. The aforesaid curable, isocyanato-containing thermoplastic mass can be stored for relatively long periods of time or shipped to customers over great distances without undergoing any appreciable reaction at ambient conditions, e.g., about 20 C.

An extremely significant aspect is directed to the preparation of thermoplastic polyurethane resins including curable polyurethane systems. Such useful systems and/ or resins can be prepared from formulations (which include the reactants, especially the difunctional reactants, reaction conditions, and modifications thereof) as set out in the preceding aspect (re the cast polwrethanes) with the exception that there is employed at least about one equivalent of functional group, e.g., hydroxyl, primary amino, secondary amino, or mixtures thereof, from the polyfunctional chain extender per equivalent of isocyanato (NCO) from the isocyanate source. In general, a practical upper limit would be about 1.5 equivalents of functional group per equivalent of NCO. Preferred formulations contain from about 1.02 to about 1.3 equivalents of functional group per equivalent of NCO, preferably still from about 1.05 to about 1.15 equivalents of functional group per equivalent of -NCO. In other modifications, it is eminently preferred that the thermoplastic formulation contain about one equivalent of functional group per equivalent of isocyanato, especially to prepare thermoplastic elastomers which exhibit high performance characteristics.

The thermoplastic and curable polyurethane resins can 'be cured or crosslinked with an organic polyisocyanate. In this respect the novel diisocyanates of Formula I supra, the novel polyisocyanato-containing polymers exemplified previously, and/or polyisocyanates well known in the literature can be employed, e.g., publication by Siefken [Annalen, 562, pages 122-135 (1949)]. Polyisocyanates such as those produced by the phosgenation of the reaction products of aniline and formaldehyde, or p,p',p"-triphenylmethane triisocyanate, represent further illustrations.

In general, the cure can be effected by using an amount of polyisocyanate which is in stoichiometric excess necessary to react with any free or unreacted functional group from the polyfunctional chain extender. In general, from about 1 to about 10 parts by weight of additional polyisocyanate per 100 parts by weight of curable polyurethane resin is adequate to accomplish the cure for most applications. A preferred range is from about 2.5 to about 6 parts by weight of polyisocyanate per 100 parts by weight of curable stock. The additional polyisocyanate can be admixed with the curable polyurethane stock on a conventional rubber mill or in any suitable mixing device and the resulting admixture is cured in the mold at an elevated temperature, e.g., from about 125160C., in a relatively short period, e.g., a few minutes, or longer. In the mold, the cure is accomplished apparently by a reaction of excess amino or hydroxyl groups with the newly admixed polyisocyanate,

and secondly by reaction of the remaining free terminal isocyanato groups with hydrogen atoms of the urea and urethane groups to form a crosslinked resin. By this procedure, there can be obtained cured polyurethane products which range from highly elastomeric materials possessing excellent tensile strength and exceptional low brittle temperature to tough, rigid rubbery materials.

Various modifying agents can be added to the castable or curable formulations among which can be listed fillers such as carbon blacks, various clays, zinc oxide, titanium dioxide, and the like; various dyes; plasticizers such as polyesters which do not contain any reactive end-groups, organic esters of stearic and other fatty acid, metal salts of fatty acids, dioctyl phthalate, tetra'butylthiodisuccinate; glass; asbestos; and the like.

A modification of the thermoplastic and curable polyurethane resins is the preparation of formulations using diisocyanates which are well known in the literature, and subsequently effecting the cure with the novel polyisocyanates of Formulas I or XIV or the polyisocyanatocontain-ing polymers characterized by Units IX to IXF supra.

A particularly preferred aspect is directed to the preparation of elastomeric products, especially elastomeric films and elastic fibers. It has been discovered quite surprising, indeed, that there can be prepared exceptional elastic polyurethane films and fibers which are derived from substantially linear hydroxyl terminated polymers having an average molecular weight greater than about 500 and the novel diisocyanates of Formula 1 supra. The elastic films and fibers of this aspect are characterized by outsanding resistance to sunlight degradation, outstanding elongation, high resistance to fume aging, i.e., resistance to breakdown caused by nitrous oxide which is commonly found as an impurity in the atmosphere, high tensile and modulus properties, and/or good stability to oxidizing agents such as chlorine bleach.

These novel elastomeric films and fibers can be prepared by first reacting the aforesaid substantially linear hydroxyl-terminated polymer with a molar excess of the novel diisocyanate (of Formula I) to produce a substantially linear isocyanato-terminated polyurethane product (known as a prepolymer). The chain extension reaction of said prepolymer with a bifunctional curing compound in accordance with, for instance, well known cast or spinning techniques results in elastomeric films or fibers as may be the case. In a useful embodiment, the aforesaid substantially linear hydroxylterminated polymers can be linearly extended by reaction with a molar deficiency of an organic diisocyanate to yield substantially linear hydroxyl-terminated polyurethane products which products then can be reacted with a molar excess of the novel diisocyanates to obtain the prepolymer.

The substantially linear hydroxyl-terminated polymer possesses an average molecular weight of at least about 500, more suitably at least about 700, and preferably at least about 1500. The upper average molecular weight can be as high as 5000, and higher, a more suitable upper limit being about 4000. For many of the novel elastic fibers and films which exhibited a myriad of excellent characteristics, the average molecular weight of the starting hydroxyl terminal polymer did not exceed about 3800. In addition, the hydroxyl-terminated polymers possess a hydroxyl number below about 170, for example, from about to about 170; and a melting point below about 70 C., and preferably below about 50 C.

Exemplary of the substantially linear hydroxyl-terminated polymers which are contemplated include the alkylene glycols, the polyether glycols, the polyoxyalkylated diols, the polyester diols, and the initiated lactone polyester diols. The initiated lactone polyester diols are eminently preferred since elastomeric films and elastic fibers exhibiting outstanding performance characteristics can be obtained. Of the highly preferred initiated lactone polyester diols are included those which are characterized by at least about 50 mol percent of carbonylpentamethyleneoxy units therein and which possess an average molecular weight of from about 500 to about 5000, particularly from about 600 to about 4000. The remaining portion of the molecule can be comprised of, in addition to the initiator, essentially linear units derived from a cyclic carbonate such as those illustrated previously, e.g., 4,4-dimethyl-2,6-dioxacyclo- 'hexanone, 4,4-dicyanomethyl 2,6 dioxacyclohexanone, 4,4 dichloromethyl 2,6 dioxacyclohexanone, 4,4 dimethoxymethyl 2,6-dioxacyclohexanone, and the like; an oxirane compound especially ethylene oxide, 1,2-epoxypropane, the epoxybutanes, etc.; a mono-, di-, and/or trialkyl-epsilon-caprolactone such as the monomethyl-, dimethyl-, trimethyl-, monoethyl-, diethyl-, triethylepsilon-caprolactones, and others exemplified supra; an alpha, alpha dialkyl beta propiolactone such as alpha, alpha dimethyl beta propiolactone; an alpha, alpha-dihaloalkyl-beta-propiolactone as illustrated by alpha, alphadichloromethyl beta propiolactone; and others. Also highly preferred polymeric diols include the so-called initiated lactone homopolyester diols which are prepared via the reaction of an admixture of epsilon-caprolactone and an initiator which contains two groups from the class of hydroxyl, primary amino, secondary amino, and mixtures thereof, in the presence of a catalyst such as stannous dioctanoate or stannic tetraoctanoate.

Illustrative of the polyether glycols which are contemplated include those illustrated previously as well as those illustrated in column 7, lines 19 through of US. Pat. No. 2,929,804 which patent is incorporated by reference into this disclosure. Many of the polyester diols which are encompassed have been exemplified previously. Others are set forth in columns 45 of US. Pat. No. 3,097,192 which patent is incorporated by reference into this disclosure. The initiated lactone polyester diols have been thoroughly illustrated previously; others are disclosed in US. Pats. Nos. 2,878,236, 2,890,208, 2,914,556, and 2,962,524 which patents are incorporated by reference into this disclosure. The polyurethane diols of Equation XI also represent a preferred group of substantially linear hydroxyl-terminated polymers.

The minimization or elimination of crystallinity, if present in the hydroxyl-terminated polymer, can be achieved, as oftentimes is desired, by introducing pendant groups and/or unsymmetrical groups in the polymeric chain as illustrated by lower alkyl groups, e.g., methyl, ethyl, isopropyl, etc.; halo, e.g., chloro, bromo, etc.; ortho-tolylene; and similar groups which do not interfere with the subsequent polymerization under the conditions used. As is readily apparent to those skilled in the art, the choice of the proper reactants will readily yield hydroxyl-terminated polymers with the desired quantity and type of pendant and/or unsymmetrical groups. Along this vein, polymers of desired molecular weight and melting point can thus be obtained. In addition, the polymer chain can be interrupted with divalent keto, urea, urethane, etc., groups.

The hydroxyl-terminated polymer and diisocyanate can be reacted in such proportions so as to produce either a hydroxyl-terminated polyurethane product or an isocyanato-terminated polyurethane product (prepolymer). A molar ratio of diol to diisocyanate greater than one will yield the hydroxyl-terminated polyurethane whereas a molar ratio less than one will result in the prepolymer.

As indicated previously, in a particularly useful embodiment, there is employed a sufficient molar excess of hydroxyl-terminated polymer, in particular, the initiated lactone polyester diols, with relation to the organic diisocyanate so that there results substantially linear hydroxylterminated polyurethane products which have average mo- 37 lecular weights of from about 1200 to about 5000, and preferably from about 1500 to about 3800.

The hydroxyl-terminated polymers or the abovesaid hydroxyl-terminated polyurethane products then are linearly extended with the diisocyanates of Formula I. This reaction can be carried out by employing a molar ratio of diisocyanate to hydroxyl-terminated compound of from about 1.1:1 to about :1 preferably from about 1.511 to about 3.5 :1, and more preferably from about 2:1 to 2.5 :1.

In the preparation of the hydroxyl-terminated polyurethane products or the prepolymer, the reaction temperature can vary over a broad range such as noted for the isocyanato/active hydrogen (hydroxyl in this instance) section discussed previously. Of course, the optimum reaction temperature will depend, to a significant degree, upon several variables such as the choice of reactants, the use of a catalyst, the concentration of the reactants, etc. A suitable temperature range is from about C. to

about 125 C., and preferably from about 50 C. to about 100 C. The reaction time likewise is largely influenced by the correlation of the variables involved, and can vary from a few minutes to several hours, e.g., from about 0.5 to about 5 hours, and longer. The tertiary amine compounds and/or the organic metal compounds disclosed in the section which discusses the isocyanator/active hydrogen reactions can be employed as catalysts, if desired. The isocyanato/hydroxyl reactions are suitably carried out in the absence of an inert normally liquid organic vehicle, though one can be employed, if desired.

In the next step, the prepolymer which results from the above discussed isocyanato/hydroxyl reaction is reacted with a bifunctional curing compound which possesses two groups that are reactive with isocyanato groups. Examples of such curing compounds include diamines, diols, amino alcohols, hydrazino compounds, e.g., hydrazine, water, and the like. It is preferred that said curing compound have two reactive groups from the class of alcoholic hydroxyl, primary amino, and second amino. The most preferred reactive group is primary amino. It is to be understood that primary amino (NH and secondary amino (NHR) include those compounds in which the nitrogen of these amino groups is bonded to a carbon atom as in, for example, ethylenediamine, as well as those compounds in which said nitrogen (of these amino groups) is bonded to another nitrogen atom as in, for insstance, hydrazine.

The bifunctional curing compounds have been illustrated previously in the discussion of the active hydrogen compounds. Among the more desirable diamines (which term includes the monoand polyalkylene polyamines which have two and only two primary and/or secondary amino groups) are such compounds as ethylenediamine, 1,2- and 1,3-propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, the cyclohexylenediamines, the phenylenediamines, the tolylenediamines, 4,4-diaminodiphenylrnethane, mand p-xylylenediamine, 3,3-dichloro-4,4-diaminophenylmethane, benzidine, 1,5-diaminonaphthalene, piperazine, 1,4-bis(3-aminopropyl)piperazine, trans-2,5-dimethylpiperazine, and the like.

It is preferred that the diamine contain no groups other than the two reactive amino groups that are reactive with isocyanato. The said diamine can have various substituent groups including chloro, bromo, alkoxy, alkyl, and the like. Generally it is also preferred that the diamine have not more than 15 carbon atoms.

Illustrative of the various diols and amino alcohols include those exemplified previously and, in particular, ethyllene glycol, propylene glycol, 2,2-dimethyl-1,3-propanediol, para-dibenzyl alcohol, 1,4-butanediol, ethanolamine, isopropanolamine, and the like. Water and hydrazine are also useful bifunctional curing agents. The organic diamines are the preferred curing compounds, with the alkylenediamines being more preferred, and ethylenediamine being most preferred.

The ratio of reactants in the curing step can vary from about 0.8 to about 1.5 equivalents of isocyanato from the prepolymer per equivalent of functional group from the bifunctional curing compound. In many cases, it is desirable to employ approximate stoichiometric proportions of prepolymer and curing compound, i.e., in proportions such that there is present approximately one isocyanato group from the prepolymer per reactive group from the difunctional curing compound. Oftentimes, it is desirable to employ a slight stoichiometric excess of prepolymer, e.g., greater than about one equivalent and upwards to about 1.4 equivalents of isocyanato per equivalent of functional group (from the bifunctional curing compound), and preferably from about 1.05 to about 1.2 equivalents of isocyanato per equivalent of functional group.

A preferred method for carrying out the reaction of prepolymer with curing compound is to effect the reaction in an inert normally liquid organic solvent and thus form a solution from which the elastic fibers and films of the invention can be produced by conventional solution spinning and casting techniques. This can be done by dissolving the prepolymer in a solvent to make, for example, from about 5 to about 40 weight percent solid solution (percent based on total solution weight), and then adding the bifunctional curing compound to this solution. The addition will be facilitated if the curing compound is also dissolved in the same solvent. Many solvents can be used for this purpose. The essential requirecut is that the solvent be non-reactive with the prepolymer and with the curing compound. Examples of use ful solvents include acetone, dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetarnide, tetrahydrofuran, and the like. N,N-dimethylformamide is a preferred solvent. Acetone alone or in admixture with other organic vehicles such as those illustrated above represent, by far, the most preferred solvents from commercial and economic standpoints. In this respect, it should be particularly noted that commercial polyurethane fibers prepared from aromatic diisocyanates, e.g., p,p'-methylenediphenyl diisocyanate (MDI), cannot be spun or cast from an acetone system. In lieu thereof, the universal solvent for the aforesaid commercial polyurethane fibers is the expensive dimethylformamide.

The reaction between the prepolymer and the curing compound takes place readily at room temperature. Therefore, the solution can be spun into a fiber or cast into a film within a relatively short period, e.g., a few minutes, after the curing compound has been added. For example, the solution can usually be cast or spun within 10 minutes after the addition of a diamine to the prepolymer when the reactants are at a temperature of about 25 C. In making fibers, the polymer solution can be spun into a water bath, or dry spun, via conventional techniques. Liquids other than water can be employed in the bath, if desired, but water is generally preferred for economic reasons. Ethylene glycol, glycerol, and the like are illustrative of such other liquids. The temperature of the bath can be varied over a range of, for instance, 25 C. to 150 C. The fiber is recovered from the bath by conventional techniques, and can be given a post-cure to oftentimes enhance certain of the properties. A cure at elevated temperatures, for example, up to about C., and higher, for periods ranging from several minutes to several hours may be desirable in many instances. For the preparation of fibers, the cure can be conducted for a period, for example, as long as five hours whereas the cure can be increased to 16 hours, and longer, for the preparation of films. In any event, the cure, if desired, can be varied in duration to obtain the desired and optimum properties in the final product. Conventional solution casting techniques can be employed in making films.

If gelation should occur during the reaction between the prepolymer and the curing compound in the solvent, it is oftentimes desirable to add a small amount of acid to the prepolymer solution preferably before the curing 

